Static Malware Analysis

Welcome to the world of static malware analysis, a critical skill for Law Enforcement in the digital age. Imagine you’re a detective, but instead of investigating a typical crime scene, your task is to uncover the secrets hidden within computer files. These aren’t just any files—they are sophisticated pieces of software designed to steal, spy, and sometimes wreak havoc. This is the realm of malware, which stands for “malicious software.”

Static malware analysis is akin to examining a suspect’s belongings in a sealed room. You don’t interact with the suspect directly; instead, you meticulously look over their items—documents, photos, tools—to understand their intentions and capabilities without alerting them or giving them a chance to react. Similarly, in static malware analysis, you inspect the malware without running it. This process allows you to safely dissect the code and uncover what the malware is designed to do, who created it, and who might be targeted, all without the malware knowing it’s being examined.

Why is this important? Every day, cybercriminals use malware to commit crimes ranging from identity theft to espionage. As officers of the law, understanding the tools and techniques used in cybercrimes not only aids in solving these crimes but also in preventing them. By learning static malware analysis, you equip yourself with the knowledge to protect citizens and infrastructure from digital threats.

In this course, you’ll start with the basics: What is malware? How does it work? What are the common types of malware you might encounter? From there, we’ll delve into how you can use various tools to look at the malware’s code and understand its blueprint. You’ll learn how to uncover hidden functionalities and detect if a seemingly benign file is actually a trojan horse waiting to strike.

Prepare to embark on a journey into the intricate world of cybersecurity, where you’ll gain the skills to peek behind the curtain of cyber threats and ensure the safety of your community in our increasingly connected world.

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Understanding Static vs. Dynamic Malware Analysis

In the field of malware analysis, two primary techniques are employed to understand and mitigate threats: static and dynamic analysis. Each method offers unique insights and is crucial for a comprehensive approach to cybersecurity. Here, we’ll delve into the differences between these two techniques, focusing on how they can be leveraged effectively in law enforcement.

Static Analysis: Examining the Code Without Execution

Static analysis involves examining the malware without executing the code. Think of it as reading a book about bomb-making without actually building a bomb. This method allows you to inspect the inner workings of an application by analyzing its code, resources, and binary level properties. Static analysis is particularly valuable because it can be performed without the risk of triggering the malware, which could potentially cause damage or alert the attacker.

Key Aspects of Static Analysis:

Code Inspection: By reviewing the source code or binary of an application, you can identify malicious patterns, suspicious functionalities, and embedded secrets such as passwords or hidden commands.
Resource Analysis: This involves examining the embedded resources in a file, such as images, icons, or configuration files, which might contain clues about the malware’s behavior.
Binary Properties: Analyzing the binary properties of a file (e.g., file size, creation date, checksum) can help in verifying its integrity and authenticity.

Static analysis is powerful for creating signatures used to detect known malware and for preliminary assessments to understand a malware’s capabilities without risk.

Dynamic Analysis: Observing the Malware in Action

In contrast to static analysis, dynamic analysis requires running the malware in a controlled environment, often referred to as a sandbox. This technique is akin to observing a suspect in a controlled setting to see what actions they take. By executing the malware, you can monitor its behavior in real-time, which reveals how it interacts with the system and network, what files it creates or modifies, and how it communicates with external servers.

Key Aspects of Dynamic Analysis:

Behavior Observation: Dynamic analysis lets you observe how the malware operates in an environment similar to its intended targets, providing insights into its real-world impact.
System Interaction: You can see what changes the malware attempts to make on the system, such as registry modifications, file manipulations, and persistence mechanisms.
Network Activity: It allows the monitoring of network communications to identify command and control servers, data exfiltration points, and other network-based behaviors.

Dynamic analysis is crucial for uncovering the full behavior of malware, especially when its actions are only triggered under specific conditions that static analysis might not reveal.

Static Analysis of Binary Files vs. Process Dumps

In malware analysis, the context in which you analyze a suspicious entity can significantly influence what information you uncover. Two common subjects of analysis in static methods are binary files and process dumps. Each has its distinct features and offers unique insights into the behavior and structure of malicious software. Understanding the differences between analyzing a static binary file and a static dump of a process is crucial for effectively utilizing static analysis in your investigations.

Static Analysis of Binary Files

A binary file analysis involves examining the file as it exists on the disk, without considering how it behaves when executed. This is the foundational method of static analysis, where you dissect the executable file to understand its composition and potential capabilities.

Key Features of Binary File Analysis:

Binary file analysis serves as a fundamental method in static malware analysis by providing crucial insights without the need to execute the malware. This approach not only enhances safety but also aids in the initial assessment and categorization of potential threats. Below, we expand upon the types of information you can uncover through binary file analysis.

Code Structure

Understanding the code structure of a binary reveals much about its intended functionality and design. This analysis can pinpoint:

Function Calls and Control Flow: Identify which functions are called within the binary and understand the sequence of operations, which helps in predicting behavior patterns.
Headers Examination: Understanding the code structure, examining the headers of a binary provides crucial insight into its organization and functionality. This analysis involves scrutinizing sections like:
.text: This section contains the executable instructions of the binary, representing the actual code that the processor executes. Understanding the .text section helps identify the core logic and operations performed by the malware.
.data: The .data section stores initialized data that is used during the execution of the program. This may include variables, constants, or other data structures utilized by the malware.
.rsrc: The .rsrc section typically contains resources such as icons, images, or other embedded data used by the binary. Examining this section can reveal any additional payloads or functionalities hidden within the binary.
.rdata: Similar to .data, the .rdata section contains read-only data, often including strings, constants, or other static data used by the malware. Analyzing this section can uncover hardcoded values, configuration parameters, or encryption keys.
.idata: The .idata section contains the Import Address Table (IAT), which lists the functions imported by the binary from external libraries. By examining the .idata section, analysts can identify the external dependencies and API calls made by the malware, providing insights into its capabilities and behavior.
.bss: The .bss section stores uninitialized data, such as global or static variables that are initialized to zero or null values. While this section may not contain explicit data, its presence can indicate memory allocation and usage patterns within the binary.
.pdata: The .pdata section contains exception handling data used by the binary to handle structured exceptions, such as those generated by divide-by-zero errors or access violations.
.debug: The .debug section contains debugging information used by debuggers and other analysis tools to aid in understanding the binary’s structure and behavior.
.pdata: The .pdata section contains exception handling data used by the binary to handle structured exceptions, such as those generated by divide-by-zero errors or access violations.
.pdata: The .pdata section contains exception handling data used by the binary to handle structured exceptions, such as those generated by divide-by-zero errors or access violations.Entry Points: Discovering the initial point of execution within the binary can reveal how the malware activates itself.
Conditional Statements: Examining conditions and loops can help understand the circumstances under which certain malware behaviors are triggered.

Analyzing the code structure is akin to reading the blueprint of a building; it shows you the layout and design intentions before you step inside.

Static Properties

Static properties are the inherent attributes of a file that do not change unless the file itself is modified:

File Attributes: Basic attributes like file size, type, and creation/modification dates can sometimes indicate suspicious anomalies (e.g., a file that is unusually large or has a recent timestamp might warrant closer inspection).
Compilation Timestamp: The time a file was compiled can provide clues about the age of the malware and correlate it with known malware campaigns.
Embedded Resources: Resources such as icons, images, or configuration files can be disguised mechanisms for malicious operations or clues to the malware’s origin or purpose.
Strings Analysis: Extracting readable strings from the binary can reveal hardcoded paths, URLs, IP addresses, and even snippets of code or commands that provide hints about the malware’s functionality.

These static properties offer a non-invasive first look into potential red flags within a suspicious file.

Signature Analysis

Signature analysis is a robust method for quickly identifying known malware through predefined patterns or ‘signatures’:

Known Malicious Patterns: By matching file characteristics against databases of known malware signatures, you can rapidly identify established threats.
Heuristic Analysis: This technique uses broader rules or algorithms to identify unknown malware that shares characteristics with known families, offering a chance to catch new variants of known malware types.
Hash Values: Calculating hash values of files and comparing these against databases can confirm the identity of a file as a known piece of malware.

Signature analysis is essential for efficiently filtering out known threats, allowing analysts to focus on new or unknown files that require deeper investigation.

Benefits of Binary File Analysis

The primary benefit of binary file analysis lies in its ability to provide a quick, safe, and broad understanding of a file’s potential maliciousness:

Risk-Free Examination: Since the malware is not executed, there is no risk of accidental infection or triggering malicious activities.
Efficient Filtering: Quick identification and categorization of known threats streamline the process of threat management.
Preliminary Insight: Provides initial clues that can direct further, more detailed dynamic analysis if required.

Binary file analysis is an indispensable tool in the malware analyst’s arsenal, providing the first layer of defense against cyber threats by allowing a quick sift through numerous files to pinpoint those warranting more detailed examination.

Static Analysis of Process Dumps

Process dumps involve taking a snapshot of a process’s memory at a specific point in time. This snapshot includes not just the executable code, but also the data that was in memory during the execution, such as loaded libraries and runtime variables.

Key Features of Process Dump Analysis:

Process dump analysis involves examining the memory contents of a process at a specific point in time, capturing data about the program’s execution state. This type of analysis is crucial for understanding the behavior of malware in its runtime environment. Here, we expand on the types of information you can glean from analyzing process dumps of malicious software.

Runtime Data

Analyzing runtime data from process dumps can reveal much about the malware’s behavior and intent while it is actively running:

Memory Contents: Examination of what data is held in the process’s memory, including potential decryption keys, runtime configurations, or sensitive data being manipulated by the malware.
Active Functionality: Insights into what the malware is actively doing at the moment of the dump, such as data theft, file manipulation, or network activity.
Manipulated System Calls: Identification of system calls being intercepted or manipulated by the malware, which can show how it interacts with and alters the operating system.

Understanding the runtime data provides a snapshot of the malware’s active presence and operations within the system.

Dynamic Link Libraries (DLLs)

DLLs are critical components that malware may interact with to perform its functions:

Loaded DLLs: Lists which DLLs are loaded by the process, which can indicate what functionalities the malware is utilizing (e.g., network access, graphical manipulation).
Suspicious DLL Usage: Detection of unusual or unexpected DLLs that may be loaded specifically for malicious purposes, such as DLLs known to be vulnerable or commonly exploited in other malware campaigns.
DLL Function Calls: Analyzing which functions are called from these DLLs, providing deeper insight into the malware’s operations and dependencies.

DLL analysis helps in understanding the external dependencies and capabilities of malware, revealing more about its complexity and potential capabilities.

Execution Artifacts

Execution artifacts in a process dump can include a variety of elements that show how the malware interacts with its environment:

Stack Traces: Examination of the stack can reveal the sequence of function calls that led to the current state, helping trace back the actions taken by the malware.
Heap Analysis: Insights into dynamic memory allocation which might be used by malware to store data during its execution.
Unpacked or Decrypted Code: Many sophisticated malware samples initially appear benign or encrypted and only reveal malicious code during runtime, which can be captured in a dump.

These artifacts are essential for understanding not just what the malware is designed to do, but what it actually does while it is running.

Benefits of Process Dump Analysis

Process dump analysis is invaluable for detailed investigation into sophisticated malware:

Deep Insight into Behavior: It allows for an in-depth look at the malware’s operations and interactions with the system beyond what is statically coded.
Detection of Evasion Techniques: Useful in catching malware that employs techniques to hide its presence or behavior when not actively running.
Real-Time Analysis Advantages: Provides a closer look at how malware behaves under specific conditions, which might not be evident from static analysis alone.

Overall, process dump analysis offers a deeper dive into the active life of malware within its operational context, providing crucial insights that are vital for understanding advanced threats and formulating effective countermeasures. This method is particularly effective against complex and evolving malware that might evade initial detection methods or exhibit behavior that only triggers under certain conditions.

Comparing the Two Approaches

While both methods are forms of static analysis, they serve different purposes and provide insights at different levels:

Binary file analysis is about getting a broad understanding of the file’s potential capabilities and structure without execution. It’s your first line of defense, allowing for quick and safe preliminary assessments.
Process dump analysis offers a more nuanced view, showing what the malware does during execution without the risk of running it in a live environment. It’s crucial for understanding how malware behaves beyond its static code, including runtime changes and interactions with the system.

For law enforcement, combining these two approaches can enhance the ability to detect and analyze malware. Binary analysis provides a quick and efficient way to screen files, while process dump analysis digs deeper, revealing what the malware is actively designed to perform. This comprehensive view is essential for developing effective strategies to combat modern cyber threats.

Unveiling the Top 25 Malicious API Calls: Peering into Malware’s Toolbox

Picture a burglar, meticulously selecting tools from their kit to break into a house. Malware operates in a similar fashion, but instead of physical tools, it utilizes software components called Application Programming Interfaces (APIs) to infiltrate and manipulate computer systems. In this section, we’ll unveil the top 25 API calls that malware employs to wreak havoc in the digital realm. So, buckle up as we delve into the clandestine world of malicious software and uncover its favorite tricks!

CreateProcess: Just like opening a door, this API call allows malware to launch new processes, enabling it to execute its malicious code discreetly.

LoadLibrary: Imagine malware rummaging through a library to find its favorite books (or DLL files). This call loads dynamic-link libraries, often containing additional malicious functionality.

WriteFile: Similar to scribbling a note, this call allows malware to write data to files, potentially altering system configurations or exfiltrating sensitive information.

RegSetValue: Picture malware slipping into a secret chamber—the Windows Registry. This call lets it modify registry keys, granting it persistence and control over system settings.

InternetOpen: Like a spider casting its web, this call initiates internet connectivity, enabling malware to establish communication with remote servers.

HttpSendRequest: Think of this as malware sending a secret message in a bottle across the internet—it sends HTTP requests to remote servers, often to download additional malicious payloads.

CreateThread: This call is akin to spawning a new worker bee—it creates threads within a process, allowing malware to multitask and execute multiple operations simultaneously.

FindWindow: Imagine malware peeking through windows to find its target—this call helps it locate specific windows on a victim’s system, facilitating user interaction and manipulation.

EnumerateProcesses: Just like a spy counting enemy troops, this call helps malware gather intelligence by listing all running processes on a system.

GetProcAddress: Picture malware donning a disguise—it uses this call to dynamically resolve function addresses within loaded libraries, evading detection by security software.

MessageBox: This call is like malware sending a threatening letter—it displays pop-up messages on the victim’s screen, often used for ransomware demands or scare tactics.

DeleteFile: Like a skilled pickpocket, malware uses this call to quietly remove files from a victim’s system, covering its tracks and eliminating evidence.

CreateRemoteThread: Imagine malware planting seeds in someone else’s garden—this call creates threads in remote processes, enabling it to inject code and hijack system functionality.

VirtualAlloc: Similar to claiming a plot of land, this call allocates memory within a process, providing space for malware to execute its operations.

ShellExecute: Picture malware whispering commands to the system—it uses this call to execute shell commands, launching programs or opening files.

ConnectNamedPipe: Like a clandestine meeting, this call establishes connections between named pipes, facilitating communication between processes or across networks.

CryptEncrypt: Think of this as malware locking a chest—it encrypts data using cryptographic algorithms, making it unreadable without the proper decryption key.

CoCreateInstance: Imagine malware summoning a demon from a dark realm—this call creates instances of COM objects, often containing malicious functionality.

CreateFile: Like a cat burglar picking locks, this call opens files or devices, granting malware access to system resources.

WinExec: Picture malware shouting commands—it uses this call to execute programs, often launching secondary payloads or performing system modifications.

SendMessage: Similar to sending a messenger bird, this call dispatches messages to windows or controls, allowing malware to interact with user interfaces or trigger events.

GetSystemDirectory: Imagine malware mapping out a city—it uses this call to retrieve the path of the Windows system directory, aiding in file operations or payload deployment.

GetTickCount: Like a stopwatch, this call retrieves the system’s tick count, providing malware with timing information for scheduling tasks or evading analysis.

SetWindowsHookEx: Picture malware planting hidden cameras—it uses this call to install hooks, intercepting system events or user input.

InternetReadFile: This call is like malware eavesdropping on internet traffic—it reads data from internet resources, potentially harvesting sensitive information or receiving commands from remote servers.

Categorized List of DLLs Commonly Found in Malware

Here’s a categorized list of Dynamic Link Libraries (DLLs) that you might encounter during the analysis of malware, sorted by their typical usage or functionality:

Communication and Data TransferDLLs

ws2_32.dll

Description: This DLL provides access to the Windows Sockets API, a specification for network communication used to enable programmatic access to network services, particularly TCP/IP.
Usage by Malware: Malware uses ws2_32.dll to create network connections, send data over the internet, and communicate with command and control servers. It can be used to exfiltrate stolen data, download additional malicious payloads, or receive commands from attackers.
API: socket
Description: Creates a socket that is bound to a specific transport service provider.
Usage by Malware: Malware uses this API to create sockets for connecting to remote servers or listening for incoming connections.
API: connect
Description: Initiates a connection to a remote host identified by a socket.
Usage by Malware: Used to establish connections to command and control servers for sending stolen data or receiving commands.
API: send
Description: Sends data on a connected socket.
Usage by Malware: This function is critical for sending data back to attackers, such as exfiltrated files, keystrokes, or other sensitive information.
API: recv
Description: Receives data from a connected socket.
Usage by Malware: Used to receive payloads, configuration updates, or commands from a remote control server.

wininet.dll

Description: wininet.dll offers higher-level internet functions for HTTP, FTP, and Gopher protocols and is used by Windows Internet Explorer.
Usage by Malware: This DLL is commonly used by malware to handle web communications, manage cookies, and perform URL manipulations. It enables malware to interact with web-based services discreetly, often mimicking legitimate web traffic to avoid detection.
API: socket
Description: Creates a socket that is bound to a specific transport service provider.
Usage by Malware: Malware uses this API to create sockets for connecting to remote servers or listening for incoming connections.
API: connect
Description: Initiates a connection to a remote host identified by a socket.
Usage by Malware: Used to establish connections to command and control servers for sending stolen data or receiving commands.
API: send
Description: Sends data on a connected socket.
Usage by Malware: This function is critical for sending data back to attackers, such as exfiltrated files, keystrokes, or other sensitive information.
API: recv
Description: Receives data from a connected socket.
Usage by Malware: Used to receive payloads, configuration updates, or commands from a remote control server.

wsock32.dll

Description: Similar to ws2_32.dll, wsock32.dll provides access to the Windows Sockets interface but is an older variant. It supports creating and managing socket connections, which are essential for network communications.
Usage by Malware: Malware utilizes wsock32.dll to establish network connections for communication with remote servers, performing tasks similar to those using ws2_32.dll. It’s less commonly used in newer malware given the prevalence of ws2_32.dll but might appear in attacks targeting older systems.
API: socket (Similar usage as in ws2_32.dll)
API: connect (Similar usage as in ws2_32.dll)

netapi32.dll

Description: This DLL includes functions for network administration, including local and remote management of accounts, network configurations, and resources.
Usage by Malware: Malware leverages netapi32.dll to manipulate network settings, spread laterally across a network, and access or modify network shares. It can be used for exploiting network vulnerabilities or for conducting network reconnaissance to identify further targets within an infected network.
API: NetUserAdd
Description: Adds a user account to the server.
Usage by Malware: Used to create new accounts, potentially giving attackers more points of entry or elevating privileges within a network.
API: NetShareAdd
Description: Shares a server resource, making it accessible to network users.
Usage by Malware: Facilitates the spread of malware across a network by sharing malicious resources or tools.

mswsock.dll

Description: mswsock.dll provides enhancements to the standard socket functions, offering additional capabilities for network operations.
Usage by Malware: This DLL is used by malware for advanced network communications, supporting the establishment of sophisticated network connections that might bypass traditional monitoring, enhancing data exfiltration or remote control functionalities.
API: TransmitPackets
Description: Simplifies high-performance, multi-point data transmission over connected sockets.
Usage by Malware: Used for efficient data transfer, particularly in network propagation or data exfiltration scenarios.

httpapi.dll

Description: httpapi.dll supports the HTTP protocol stack in Windows, allowing applications to act as HTTP clients or servers without relying on Internet Information Services (IIS).
Usage by Malware: Malware can exploit httpapi.dll to create its own HTTP server on the infected machine, which can be used to receive commands or send data directly over the network, facilitating covert communication channels.
API: HttpCreateHttpHandle
Description: Creates an HTTP request queue.
Usage by Malware: Malware can use this to set up an HTTP server on the infected machine, receiving commands or transmitting data covertly.
API: HttpAddUrl
Description: Registers a given URL with an HTTP server session.
Usage by Malware: Allows malware to listen on specific URLs, handling HTTP requests directly, useful for command and control or data exfiltration servers running on compromised hosts.

Registry Access DLLs

advapi32.dll

Description: advapi32.dll contains advanced API functions related to the Windows registry, service control, and security. It is essential for handling many lower-level, security-related tasks in Windows.
Usage by Malware: This DLL is crucial for malware when modifying system settings, managing services, and changing permissions to maintain persistence or elevate privileges. Malware often uses advapi32.dll to access and modify registry entries, enabling it to auto-start during system boot or to hide its presence from users and system monitoring tools.
API: RegOpenKeyEx
Description: Opens the specified registry key.
Usage by Malware: Used to gain access to specific registry keys for reading or modifying system configurations, which can affect system behavior or enable persistence.
API: RegSetValueEx
Description: Sets the data and type of a specified value under a registry key.
Usage by Malware: Crucial for creating or modifying registry values to auto-start malware during system boot, disguise system settings, or disable security features.
API: RegCreateKeyEx
Description: Creates a new registry key or opens an existing one.
Usage by Malware: Allows malware to create new registry keys for storing its configurations or for other malicious purposes.
API: RegDeleteKey
Description: Deletes a specified registry key.
Usage by Malware: Used to remove traces or disable applications and services (e.g., security software) by deleting their registry keys.
API: RegEnumValue
Description: Enumerates the values for the specified open registry key.
Usage by Malware: Helps in gathering information from the system registry, which can be used to adjust the malware’s behavior based on existing settings.

File Access DLLs

kernel32.dll

Description: kernel32.dll is a core component of the Windows operating system and provides applications with access to fundamental resources such as memory, processes, and files.
Usage by Malware: Malware utilizes kernel32.dll for a variety of file operations including creating, reading, writing, and deleting files. This DLL is also used to manipulate processes and memory, which are crucial for maintaining persistence, hiding its presence, or loading additional malicious modules.
API: OpenProcess
Description: Opens an existing local process object.
Usage by Malware: Allows malware to gain access to other processes for purposes such as injecting code, terminating processes, or altering process behavior.
API: VirtualAlloc
Description: Reserves or commits a region of pages in the virtual address space of the calling process.
Usage by Malware: Used to allocate memory in a process’s address space, commonly for unpacking or injecting malicious code dynamically.
API: VirtualFree
Description: Releases, decommits, or releases and decommits a region of memory within the virtual address space of a calling process.
Usage by Malware: Helps in cleaning up or hiding its memory usage by de-allocating memory previously used for malicious activities.
API: VirtualProtect
Description: Changes the protection on a region of committed pages in the virtual address space of the calling process.
Usage by Malware: Often used to change the permissions on a region of memory to execute injected code or protect its own malicious code from being overwritten.
API: CreateProcess
Description: Creates a new process and its primary thread. The new process runs in the security context of the calling process.
Usage by Malware: Enables malware to spawn new processes, which can be used for executing additional malicious payloads or for process hollowing techniques.
API: ExitProcess
Description: Ends the calling process and all its threads.
Usage by Malware: Used by malware to terminate its process as part of cleanup routines or to avoid detection after performing malicious tasks.
API: GetModuleHandle
Description: Retrieves a module handle for the specified module. The module must be loaded by the calling process.
Usage by Malware: Allows malware to locate loaded modules within its process, useful for finding addresses of functions to be hooked or manipulated.
API: LoadLibrary
Description: Loads the specified module into the address space of the calling process.
Usage by Malware: Used to load additional malicious DLLs or other libraries required for its operations dynamically.
API: GetProcAddress
Description: Retrieves the address of an exported function or variable from the specified dynamic-link library (DLL).
Usage by Malware: Critical for malware that needs to dynamically locate and invoke system or third-party library functions based on their names at runtime, often used in conjunction with LoadLibrary.
API: SetFileAttributes
Description: Sets the attributes of a file or directory.
Usage by Malware: Can be used by malware to modify file attributes, such as setting files to be hidden or read-only to conceal its presence or protect its files from deletion.
API: CopyFile
Description: Copies an existing file to a new file, notifying the application of its progress through a callback function.
Usage by Malware: Allows for replication of itself or spreading to other locations within the host system or across networked computers.
API: MoveFile
Description: Moves a file or directory, including its children.
Usage by Malware: Utilized to reorganize malicious files or dependencies within the system to avoid detection or to comply with a specific attack sequence.
API: CreateFile
Description: Creates or opens a file or I/O device.
Usage by Malware: Used to create new files or open existing ones, enabling the malware to read, write, or execute files as part of its operation.
API: WriteFile
Description: Writes data to the specified file or input/output (I/O) device.
Usage by Malware: This is used to modify files or append new data to files, such as logging keystrokes or storing data before exfiltration.
API: ReadFile
Description: Reads data from a file or input/output (I/O) device.
Usage by Malware: Enables malware to read sensitive information from files, which could include user data, configuration files, or other critical data.
API: DeleteFile
Description: Deletes an existing file.
Usage by Malware: Allows malware to remove files that could be logs, backups, or other security-related files to hinder detection and mitigation efforts.
API: FindFirstFile/FindNextFile
Description: Searches a directory for a file or subdirectory with a name that matches a specific name. FindFirstFile initiates the search, and FindNextFile continues it.
Usage by Malware: These functions are commonly used by malware to scan directories for files of interest, such as documents, database files, or configuration files that it might encrypt, steal, or manipulate.
API: SetThreadContext
Description: Sets the context for a specified thread.
Usage by Malware: Used in code injection techniques, particularly in process hollowing or thread hijacking scenarios, to manipulate the execution flow of a target process.
API: ResumeThread
Description: Decreases the suspend count on a thread. If it becomes zero, the execution of the thread is resumed.
Usage by Malware: Often used after SetThreadContext to restart a thread within a process it has injected code into, enabling the execution of malicious code within the context of another application.
API: CreateMutex
Description: Creates or opens a named or unnamed mutex object.
Usage by Malware: Used to manage access to resources, or more commonly by malware, to ensure that only one instance of itself runs at any given time (singleton mutex).
API: WaitForSingleObject
Description: Waits until the specified object is in the signaled state or the time-out interval elapses.
Usage by Malware: Utilized to synchronize the execution of threads, especially in complex malware that operates multi-threaded tasks such as network communication or file encryption.
API: CreateRemoteThread
Description: Creates a thread that runs in the virtual address space of another process.
Usage by Malware: Crucial for executing remote code injection, allowing malware to run its code within the address space of another process, thereby masquerading its malicious activities under legitimate processes.
API: GetCurrentProcessId
Description: Retrieves the process identifier of the calling process.
Usage by Malware: Often used to obtain the process ID for use in manipulation or attack routines, such as targeting specific processes for injection or termination.
API: TerminateProcess
Description: Ends the specified process and all of its threads.
Usage by Malware: Used to forcefully stop processes, especially security-related processes, to disable protections and clear the way for unhindered malicious activity.
API: GetTickCount
Description: Retrieves the number of milliseconds that have elapsed since the system was started.
Usage by Malware: Used in timing attacks or to generate pseudo-random values for use in operations like encryption keys or network communication timing.
API: GetLocalTime
Description: Retrieves the current local date and time.
Usage by Malware: Can be used to trigger actions at specific times, adjust behaviors based on time, or timestamp events like logging or data exfiltration.
API: GetSystemTime
Description: Retrieves the current system date and time, expressed in Coordinated Universal Time (UTC).
Usage by Malware: Similar to GetLocalTime, used for timing operations or for operations that need to be synchronized across different geographic locations.

ntdll.dll

Description: ntdll.dll serves as a user-mode layer that provides system services to Windows applications. It contains lower-level functions performed by the kernel that are not exposed directly to end applications.
Usage by Malware: This DLL is used by malware for more sophisticated file and memory management tasks. Malware can use ntdll.dll to access advanced system-level calls for manipulating files and processes, often bypassing standard API monitoring and security checks.
API: NtCreateFile
Description: Creates or opens a file, directory, I/O device, or other file system object.
Usage by Malware: Provides more direct access to the file system, bypassing some layers of the Windows API for stealthier file operations.
API: NtReadFile
Description: Reads data from a file or device.
Usage by Malware: Used similarly to ReadFile, but at a lower system level to potentially avoid detection by security software monitoring higher-level API calls.
API: NtWriteFile
Description: Writes data to a file or device.
Usage by Malware: Allows for direct writing to files at a lower system level, useful for stealthy operations like implanting data or modifying system files.

shlwapi.dll

Description: The shlwapi.dll (Shell Lightweight Utility API) provides a broad set of utility functions that are often utilized by applications to perform various tasks such as string manipulation, file path operations, and URL handling. Malware can leverage these functionalities for its own nefarious purposes. Here are additional APIs from shlwapi.dll that are frequently used by malware.
Usage by Malware: Malware uses shlwapi.dll for manipulating file paths and URLs, handling registry data, and performing various utility functions which can help in data theft or configuration. It’s especially useful for normalizing paths or managing complex strings, which can aid in obfuscating file locations or registry paths.
API: PathAppend
Description: Appends one path to another, ensuring the result is a properly formed path.
Usage by Malware: Useful for dynamically building file paths that the malware needs to access or modify.
API: PathCombine
Description: Combines two paths into a single path.
Usage by Malware: Useful for constructing file paths dynamically, aiding in the concealment of file locations or the organization of malware components.
API: PathStripPath
Description: Removes the path portion from a fully qualified path and filename, leaving only the filename.
Usage by Malware: Helps in isolating filenames from paths, which can be used when creating or manipulating files.
API: PathRemoveFileSpec
Description: Removes the trailing file name and backslash from a path, if present.
Usage by Malware: Utilized to manipulate file paths dynamically, particularly when navigating through directories to place or modify files covertly.
API: SHCreateDirectoryEx
Description: Creates a new directory, and if necessary, makes all the intermediate directories in a specified path.
Usage by Malware: Helps in setting up a directory structure required for dropping additional payloads or organizing stolen data before exfiltration.
API: SHDeleteKey
Description: Deletes a specified registry key and all its subkeys.
Usage by Malware: Used by malware to remove traces of itself or other applications from the registry, potentially disabling security software or cleanup tools.
API: SHGetValue
Description: Retrieves a value from the specified key in the registry.
Usage by Malware: Can be used to read configuration settings or other values from the registry that might dictate malware behavior or targets.
API: SHSetValue
Description: Sets a registry value under an open registry key.
Usage by Malware: Allows malware to write or modify registry values for purposes such as establishing persistence or launching at system startup.
API: StrCmpI
Description: Compares two strings, ignoring case.
Usage by Malware: Used to compare file paths or registry entries, aiding in the decision-making process of the malware based on configuration or environment.
API: UrlEscape
Description: Converts characters in a URL into their escape sequences.
Usage by Malware: Important for encoding URLs, especially when sending data over the network to evade simple network-based security measures.
API: PathFindFileName
Description: Returns a pointer to the last component of a path string.
Usage by Malware: Enables malware to extract the file name from a path, useful in scenarios where the malware needs to analyze or modify specific files based on their names.
API: PathFindExtension
Description: Retrieves the address of the period character that precedes the file name extension in a path.
Usage by Malware: Helps in identifying and manipulating file types, crucial for operations like payload activation or spreading mechanisms that rely on file extensions.
API: PathIsRelative
Description: Determines if a path string is a relative path.
Usage by Malware: Used to ascertain how a path should be handled, whether it needs conversion to an absolute path for certain operations or can be used as is.
API: SHFileOperation
Description: Performs file operations such as moving, renaming, deleting, or copying files.
Usage by Malware: Enables malware to manipulate files on a large scale, such as deleting security logs, copying itself to different directories, or moving sensitive files to a location controlled by the attacker.
API: PathIsDirectory
Description: Determines whether a given path is a directory.
Usage by Malware: Helps malware decide how to handle specific paths—whether to drop additional payloads in directories or execute specific actions based on directory presence.
API: PathCanonicalize
Description: Canonicalizes a path, simplifying it and removing any redundant elements such as “..” or “.” in paths.
Usage by Malware: Useful for standardizing paths that malware retrieves from compromised systems, ensuring they are in a usable format for further operations.
API: StrTrim
Description: Removes leading and trailing whitespace and other specified characters from a string.
Usage by Malware: Often used to clean up file paths or command inputs retrieved during execution, aiding in evasion and ensuring commands execute correctly.
API: PathFindOnPath
Description: Searches for a file in a list of specified paths or in the system’s PATH environment variable.
Usage by Malware: Enables malware to locate executable files or libraries it may need to load dynamically without specifying an absolute path.
API: SHRegGetValue
Description: Retrieves a data value from the registry, handling various data types and paths.
Usage by Malware: Used for extracting configuration or key values that may control the malware’s behavior or store encrypted or encoded data.
API: UrlUnescape
Description: Converts URL escape sequences back to ordinary characters.
Usage by Malware: Essential for decoding URLs or data received from a C2 server that may be in an encoded format to avoid detection.
API: SHRegWriteUSValue
Description: Writes data in a user-specific location in the registry, considering the current user’s environment.
Usage by Malware: Allows malware to customize its registry entries per user, making its activity on multi-user systems more targeted and less detectable.
API: SHRegDeleteEmptyUSKey
Description: Deletes an empty registry key in a user-specific path, considering current user settings.
Usage by Malware: Used to clean up after itself, especially when attempting to remove traces of its configuration or installation.
API: PathUnExpandEnvStrings
Description: Reverses the expansion of environment variables in a path string.
Usage by Malware: Utilized by malware to convert absolute paths back to environment-variable based paths, which can be useful for generalizing paths to work on different systems.

System Access DLLs

user32.dll

Description: user32.dll manages the Windows user interface including windows, menus, and dialogs. It handles user input, window management, and message passing.
Usage by Malware: Malware uses user32.dll to intercept and manipulate user input, simulate keystrokes, or create fake user interfaces. It can also manage windows to hide malicious windows or pop-ups from the user.
API: CreateWindowEx
Description: Creates an overlapped, pop-up, or child window with an extended style.
Usage by Malware: Malware uses this API to create hidden or disguised windows that can intercept user inputs or display deceptive information.
API: SetWindowsHookEx
Description: Installs an application-defined hook procedure into a hook chain.
Usage by Malware: This function is often used by keyloggers to intercept keystrokes and other system messages.
API: SendMessage
Description: Sends the specified message to a window or windows.
Usage by Malware: Used to send messages between processes or to manipulate the behavior of applications or UI components.
API: EnumWindows
Description: Enumerates all top-level windows on the screen by passing the handle to each window, in turn, to an application-defined callback function.
Usage by Malware: Malware can use this API to find windows of interest, such as banking software, and either monitor them or manipulate them.
API: GetAsyncKeyState
Description: Determines whether a key is up or down at the time the function is called, and whether the key was pressed after a previous call to GetAsyncKeyState.
Usage by Malware: Often used in keylogging functionalities to capture user keystrokes, especially for recording passwords and other sensitive information.
API: GetForegroundWindow
Description: Retrieves a handle to the foreground window (the window with which the user is currently working).
Usage by Malware: Useful for determining which application the user is currently using, allowing malware to activate specific logging or manipulation routines when certain applications are open.
API: SetForegroundWindow
Description: Brings the thread that created the specified window into the foreground and activates the window.
Usage by Malware: Can be used to force malicious or phishing windows to the front, tricking users into interacting with them.
API: BlockInput
Description: Blocks keyboard and mouse input events from reaching applications.
Usage by Malware: Employed to prevent users from intervening during critical malicious operations, such as data encryption by ransomware.
API: ShowWindow
Description: Sets the specified window’s show state, including commands to minimize, maximize, or hide the window.
Usage by Malware: Used to hide malicious windows or dialogs from the user, making the malware less detectable.
API: UpdateWindow
Description: Updates the client area of the specified window by sending a WM_PAINT message to the window if the window’s update region is not empty.
Usage by Malware: Helps to refresh and redraw custom UI elements created by malware to ensure they appear legitimate and up-to-date.
API: FindWindow
Description: Retrieves a handle to the top-level window whose class name and window name match the specified strings.
Usage by Malware: This API can be used to locate windows associated with security software or other specific applications that malware might want to close or manipulate.
API: PostMessage
Description: Places (posts) a message in the message queue associated with the thread that created the specified window and returns without waiting for the thread to process the message.
Usage by Malware: Allows malware to asynchronously trigger events or commands within other applications, potentially as part of an attack to control or disrupt application behavior.
API: GetWindowRect
Description: Retrieves the dimensions of the bounding rectangle of the specified window.
Usage by Malware: Useful for determining the size and position of application windows for further GUI manipulation or for taking screenshots of specific windows.

gdi32.dll

Description: gdi32.dll handles the graphical device interface in Windows, dealing with tasks related to drawing graphics, rendering fonts, and managing palettes.
Usage by Malware: This DLL is used by malware for tasks that require drawing on the screen, capturing screenshots, or manipulating graphical content. It can be used to create deceptive visual elements that trick users into divulging sensitive information.
API: BitBlt
Description: Performs a bit-block transfer of the color data corresponding to a rectangle of pixels from the specified source device context into a destination device context.
Usage by Malware: This API can be used to capture screenshots of the user’s desktop, which can then be sent to the attacker.
API: CreateFontIndirect
Description: Creates a logical font with the specified characteristics.
Usage by Malware: Malware might use this to manipulate text rendering in an application for phishing purposes or to overlay deceptive text over legitimate applications.
API: TextOut
Description: Writes a character string at the specified location, using the currently selected font, background color, and text color.
Usage by Malware: Used to draw custom text on the screen to mislead the user or to create fake user interface elements.

shell32.dll

Description: shell32.dll is integral to the Windows Shell API, which deals with desktop, file management, and other shell functions.
Usage by Malware: Malware utilizes shell32.dll to perform actions like accessing special folders (like Documents or Startup), modifying system menus, and interacting with the file system more extensively. It also helps in creating shortcuts that facilitate the spread or execution of malware components.
API: CreateWindowEx
Description: Creates an overlapped, pop-up, or child window with an extended style. It is used to specify additional window properties and can create a variety of types of windows depending on the parameters passed.
Usage by Malware: Malware can use CreateWindowEx to create stealthy or hidden windows that capture user inputs, display misleading information, or monitor user activities. It can also create windows that mimic legitimate software prompts or system messages to deceive users into executing harmful actions.
API: SetWindowsHookEx
Description: Installs an application-defined hook procedure into a hook chain. Hooks can monitor a wide range of system activities such as keystrokes, mouse movements, and system messages.
Usage by Malware: This API is often exploited by keyloggers and spyware to intercept and record keystrokes, capture mouse clicks, or read other input from the user, thereby compromising personal data and privacy.
API: SendMessage
Description: Sends the specified message to a window or windows. It calls the window procedure for the specified window and does not return until the window procedure has processed the message.
Usage by Malware: Malware uses SendMessage to interact with other applications, modify application behavior, send commands, or trigger events. It can be used to fill out forms automatically, press buttons, or even close security alerts without user interaction.
API: ShellExecute / ShellExecuteEx
Description: Performs an operation on a specified file. ShellExecuteEx extends ShellExecute capabilities by allowing more detailed control over the action performed.
Usage by Malware: These functions are widely used by malware to run executable files, open documents, or launch applications which may lead to the spread of infection, execution of malicious scripts, or activation of payloads. It can also be used to open web pages that perform phishing attacks or download additional malware.
API: SHGetFolderPath
Description: Retrieves the path of a special folder, identified by its CSIDL, where applications can store data common to all users.
Usage by Malware: Malware often uses SHGetFolderPath to locate system directories such as the Startup folder, Application Data, or System folder to place malicious files for persistence or to ensure execution on system startup.
API: SHFileOperation
Description: Performs file operations like moving, copying, renaming, or deleting files as specified by the caller. It can operate on multiple files and can also support showing progress dialogs.
Usage by Malware: This function is utilized by malware for managing files within the system, such as spreading copies of itself, deleting critical files, or rearranging content to hide its tracks or confuse users and security software.
API: DragAcceptFiles
Description: Registers a window as being open to accepting dropped files. This function is crucial for implementing drag-and-drop functionality.
Usage by Malware: By enabling drag-and-drop capabilities, malware can trick users into dropping sensitive documents or executable files into a rogue application window, which can then process the files in harmful ways, such as extracting sensitive data or initiating unauthorized actions.
API: Shell_NotifyIcon
Description: Adds, modifies, or deletes an icon in the system tray (notification area).
Usage by Malware: Malware can exploit this function to add deceptive icons to the system tray that mimic legitimate applications, thereby misleading the user about the true nature of the running processes. It can also be used to hide malicious notifications or simulate system alerts to manipulate user behavior.
API: SHGetFileInfo
Description: Retrieves properties such as the attributes, icon, and type description for a specified file or folder.
Usage by Malware: This API allows malware to gather information about system files or user documents to tailor its attack or to choose files for stealing or encryption based on their attributes or types.
API: SHCreateDirectoryEx
Description: Ensures the creation of a directory; if the intermediate folders do not exist, it will create them as needed.
Usage by Malware: Malware uses this API to create nested directories for hiding its components deep within the system directories or to set up a directory structure that supports its persistence mechanisms or operational requirements.
API: ExtractAssociatedIcon
Description: Retrieves an icon handle associated with a file or program, based on its file type or executable.
Usage by Malware: This function can be used by malware to extract icons from legitimate applications to use as decoys, making malicious files appear trustworthy or familiar to unsuspecting users.
API: SHBrowseForFolder
Description: Displays a dialog box that enables the user to select a folder, providing a graphical interface to navigate the file system.
Usage by Malware: Malware might use this API in custom configuration tools or during installation processes to trick users into selecting important directories for harmful actions, such as data theft or the installation of further malicious components.
API: ShellAbout
Description: Displays an “About” dialog box which can contain information about the application, such as version, product name, copyright notice, and other text or graphical elements.
Usage by Malware: While less commonly used for direct malicious activities, this API can be used by malware to mimic legitimate application dialogs to reinforce the disguise, making the malware appear as a legitimate software component.
API: SHAppBarMessage
Description: Sends a message to the system to perform an action related to an application desktop toolbar (appbar) such as creating, removing, or modifying its position.
Usage by Malware: This API could be utilized by malware to manipulate the taskbar or appbars to create additional screen real estate that can be used for displaying advertisements, redirecting user inputs, or simply as part of a user interface spoofing attack.
API: SHGetDesktopFolder
Description: Retrieves the IShellFolder interface for the desktop folder, which is the root of the Shell’s namespace.
Usage by Malware: Allows malware to manipulate desktop items directly, such as creating malicious shortcuts or hiding certain icons to confuse the user or obscure its presence.
API: SHQueryRecycleBin
Description: Retrieves the size and number of items in the Recycle Bin on a specified drive.
Usage by Malware: Can be used to monitor for deleted files that may still be recoverable for malicious purposes or to clean out the Recycle Bin to eliminate traces of malicious activities.
API: SHGetSpecialFolderLocation
Description: Retrieves the location of a special folder, identified by a CSIDL value, and returns a pointer to an item identifier list (PIDL) of the folder.
Usage by Malware: Useful for finding important system folders like Startup or Program Files to place malicious executables or links for persistence and execution.
API: SHSetLocalizedName
Description: Assigns a localized name to a file, folder, or drive that shows up in the user interface.
Usage by Malware: Can rename malware-installed files or folders to appear legitimate or related to genuine software, reducing suspicion and enhancing stealth.
API: SHChangeNotify
Description: Notifies the system of an event that an application has performed, such as creating, deleting, modifying, or renaming items.
Usage by Malware: Used by malware to refresh Explorer views to reflect changes it makes, like hiding or creating new files, or to disguise its modifications as normal system updates.
API: SHGetStockIconInfo
Description: Retrieves information about a stock Shell icon.
Usage by Malware: Malware may use this API to fetch system icons for use in creating convincing fake files or shortcuts, making them appear as legitimate system components.
API: SHGetKnownFolderIDList
Description: Retrieves the item identifier list (PIDL) for a known folder identified by a known folder ID.
Usage by Malware: Enables malware to accurately locate special folders across different versions of Windows, ensuring that it can consistently find and manipulate user data or system settings.
API: SHGetPropertyStoreForWindow
Description: Retrieves the property store for the specified window, allowing access to window properties and settings.
Usage by Malware: Could potentially be used to manipulate window properties to hide malicious windows or to obtain information about window settings for further exploits.
API: SHGetImageList
Description: Retrieves a handle to an image list used by the Shell.
Usage by Malware: Can be utilized to obtain system images for use in phishing attacks or to replace legitimate system images with malicious ones.
API: SHSetFolderPath
Description: Redirects a known folder to a new location.
Usage by Malware: Allows malware to redirect data writes intended for well-known directories to controlled or monitored locations.
API: SHGetIconOverlayIndex
Description: Retrieves the overlay index of an icon in the system image list.
Usage by Malware: Used to apply specific icon overlays to files, potentially disguising malicious files as protected or synchronized files, misleading the user.
API: SHLoadNonloadedIconOverlayIdentifiers
Description: Ensures that all registered overlay identifiers are loaded into the system.
Usage by Malware: Could be used in complex icon manipulation schemes where ensuring all overlays are loaded is necessary for the malware’s visual deception strategies.
API: SHMapPIDLToSystemImageListIndex
Description: Maps a PIDL to an index in the system image list.
Usage by Malware: This can assist malware in selecting appropriate system icons for files or folders it creates or modifies, enhancing its ability to blend in with the native system environment.

Process and Thread Management

kernel32.dll

Description: As mentioned previously, kernel32.dll is essential for managing system resources, including processes and threads. It provides APIs for creating, managing, and terminating processes and threads.
Usage by Malware: Malware uses kernel32.dll to manage its own processes and threads for executing parallel tasks, maintaining persistence, and evading detection by manipulating its execution state.

ntdll.dll

Description: ntdll.dll contains more low-level functions used by Windows NT-based operating systems, including those related to process and thread management.
Usage by Malware: Through ntdll.dll, malware can directly interact with the Windows kernel, accessing advanced system services for process and thread manipulation, which can be used to hide its presence or monitor system activities more stealthily.

psapi.dll

Description: psapi.dll (Process Status API) allows applications to retrieve information about processes and device drivers running on a system.
Usage by Malware: Malware can leverage psapi.dll to enumerate processes and modules for information gathering, determining targets for injection, or identifying security software that may be running on the system.

Cryptographic Functions

crypt32.dll

Description: crypt32.dll provides functions for certificate and cryptography management, including handling certificate storage and performing encoding and decoding functions.
Usage by Malware: Malware may use crypt32.dll to manage certificates, create fake certificates for spoofing identities, or decode data extracted from a system.

bcrypt.dll

Description: bcrypt.dll provides a cryptographic primitive library, which includes algorithms for hashing, encryption, and decryption.
Usage by Malware: This DLL is often used by malware for data encryption and hashing to secure its communications or encrypt files during ransomware attacks.

cryptui.dll

Description: cryptui.dll supports the display of cryptographic user interface elements, mainly dialogs related to certificates and security warnings.
Usage by Malware: Malware might utilize cryptui.dll to mimic security dialogs to deceive users into taking undesirable actions, such as granting permissions or disabling security features.

ncrypt.dll

Description: ncrypt.dll provides functions for managing key storage and performing cryptographic operations in a more secure manner.
Usage by Malware: It can be used by malware to securely store cryptographic keys or perform cryptographic operations that are harder for security tools to detect or intercept.

Compression and Decompression

cabinet.dll

Description: cabinet.dll is used for cabinet file operations, which include compression and decompression functions for cabinet files (.cab) used in Windows installations and updates.
Usage by Malware: Malware may use this DLL to compress or decompress data as part of its payload delivery or data exfiltration techniques, utilizing common file formats to blend in with legitimate operations.
API: FCICreate
Description: Creates a new cabinet or folder.
Usage by Malware: Used by malware to create cabinet files that may contain compressed data, which can be part of an installation or update process disguising malicious activities.
API: FCIAddFile
Description: Adds files to a cabinet.
Usage by Malware: Malware can use this API to add malicious files to a .cab file, which may be later unpacked during execution or distribution.
API: FDICopy
Description: Extracts files from a cabinet.
Usage by Malware: This function allows malware to extract and execute contents of a .cab file that were previously compressed, potentially as part of a multi-stage infection process.

zipfldr.dll

Description: zipfldr.dll manages ZIP file operations in Windows, providing native support for ZIP file creation and extraction.
Usage by Malware: This DLL can be used by malware to handle ZIP files for packaging or unpacking data, which can be useful in both spreading the malware and managing stolen data.
API: ZipFile
Description: Compresses files into a ZIP file.
Usage by Malware: Malware can use this to compress stolen data before exfiltration, reducing the size and sometimes helping to evade detection by simple file type filters.
API: UnzipFile
Description: Extracts files from a ZIP archive.
Usage by Malware: Allows malware to unpack components or payloads downloaded from a command and control server, or to release other malicious contents stored within a ZIP file on the compromised system.

Dynamic Data Exchange

user32.dll

Description: As previously noted, user32.dll handles user interface elements, including windows and dialog management, but it also plays a role in Dynamic Data Exchange (DDE), which allows applications to share data.
Usage by Malware: Malware can exploit DDE features provided by user32.dll to execute arbitrary commands, communicate with or control other applications, or siphon data from compromised applications, often without the user’s knowledge.
API: SendMessage (used for DDE)
Description: Sends a message to a window or windows, which can include DDE messages like WM_DDE_INITIATE, WM_DDE_EXECUTE, etc.
Usage by Malware: This API can be used by malware to initiate a DDE conversation with other applications to execute commands or to exfiltrate data through seemingly benign inter-application communication.
API: DdeConnect
Description: Establishes a conversation between a client application and a server application.
Usage by Malware: Malware might exploit this function to connect to another DDE-capable application to manipulate it or use it as a part of a command and control mechanism.
API: DdeClientTransaction
Description: Performs data transactions between a client and a server in a DDE conversation. It can send data to or request data from a server.
Usage by Malware: Used to send commands or retrieve data from other applications, enabling the malware to perform actions covertly, such as gathering sensitive information or executing commands without direct file execution.

Hardware and Device Access

hid.dll

Description: hid.dll supports interactions with human interface devices like keyboards, mice, and game controllers.
Usage by Malware: This DLL can be used by malware to monitor or intercept input from devices, enabling keylogging or command execution based on specific user inputs.
API: HidD_GetAttributes
Description: Retrieves the attributes of a specified HID device, such as vendor ID, product ID, and version number.
Usage by Malware: This function can be used by malware to identify specific hardware devices connected to the system, potentially targeting devices known for vulnerabilities or specific functionalities.
API: HidD_GetFeature
Description: Retrieves a feature report from a top-level collection of a HID.
Usage by Malware: Malware might use this to intercept or modify configuration settings of HID devices, which could alter behavior or enable unauthorized activities.
API: HidD_SetFeature
Description: Sends a feature report to a top-level collection of a HID.
Usage by Malware: This API can be utilized to program HID devices to perform malicious activities or to exfiltrate data in a covert manner.
HidD_GetInputReport
Description: Retrieves an input report from a top-level collection of a HID. Input reports are sent by the device to the host and can include data like the state of input controls.
Usage by Malware: This function can be used to intercept input data from HIDs in real-time, which could potentially include capturing sequences of keystrokes from a HID keyboard or movements from a HID mouse.
HidD_SetInputReport
Description: Sends an input report to a top-level collection of a HID. This can modify the incoming reports before they are processed by other applications.
Usage by Malware: Although more commonly used for legitimate purposes like updating device settings, malware could theoretically use this function to inject false inputs, disrupting user interactions or simulating user actions.
HidD_GetFeature and HidD_SetFeature
Description: These functions handle feature reports, which are used to exchange data between a device and a host that does not fit the model of input and output reports. Feature reports can be used both to send data to the device and to alter or retrieve a device’s configuration.
Usage by Malware: Malware can use these functions to change configurations or retrieve sensitive information that might be stored in the device’s feature set, which could include configuration settings or other data.
HidD_GetAttributes
Description: Obtains attributes of a specified HID, including vendor ID, product ID, and version number.
Usage by Malware: Useful for identifying specific devices connected to a system. Malware could use this information to tailor its activities based on the specific hardware present, or to identify high-value targets (such as devices known for vulnerabilities).
HidD_GetSerialNumberString
Description: Retrieves the serial number string for a HID, if one exists.
Usage by Malware: This could be used to track individual devices across different systems or sessions, particularly useful in targeted espionage or data exfiltration scenarios.
HidD_GetManufacturerString and HidD_GetProductString
Description: Retrieve strings describing the manufacturer and product name of a HID.
Usage by Malware: These can be used to gather more detailed information about the connected devices, aiding in more sophisticated hardware-specific attacks or in avoiding detection on systems with security devices known to interfere with malware.

setupapi.dll

Description: setupapi.dll provides functions necessary for device installation, configuration, and maintenance, including driver installations and updates.
Usage by Malware: Malware might use setupapi.dll to install malicious drivers, modify hardware settings, or disguise itself as a legitimate hardware-related operation, which can be particularly effective in persistent attacks.
API: SetupDiGetClassDevs
Description: Returns a handle to a device information set that contains requested device information elements for a local computer.
Usage by Malware: Used by malware to enumerate devices connected to a system, identifying potential targets for infection or manipulation.
API: SetupDiEnumDeviceInterfaces
Description: Enumerates the device interfaces that are contained in a device information set.
Usage by Malware: This function allows malware to find specific device interfaces that it can manipulate, potentially to interact with or control hardware devices directly.
API: SetupDiInstallDevice
Description: Installs a device.
Usage by Malware: Can be used by malware to install malicious or altered drivers, which could subvert the operating system or other software, facilitating deeper system control or persistence.

Window Management and User Interface

uxtheme.dll

Description: uxtheme.dll is involved in applying visual styles and themes to the Windows user interface.
Usage by Malware: By leveraging uxtheme.dll, malware can modify or mimic user interface elements to blend in with the system or to create convincing phishing elements, such as fake error messages or security prompts.

dwmapi.dll

Description: dwmapi.dll controls functions related to the Desktop Window Manager (DWM), which manages window effects and transparency in Windows, particularly Aero effects.
Usage by Malware: Malware can use dwmapi.dll to manipulate window properties for stealth, such as hiding windows or creating visually deceptive overlays that trick users into inputting sensitive information.

System Information Gathering

version.dll

Description: version.dll provides functions that help retrieve version information from Windows files, which includes details about the specific build, version, and platform of a file.
Usage by Malware: Malware uses version.dll to determine the operating system version and other application versions to tailor its attack methods or payloads. It helps the malware decide which vulnerabilities can be exploited based on the system or application version.
API: GetFileVersionInfo
Description: Retrieves version information for the specified file.
Usage by Malware: Malware uses this API to determine the version of system files or applications to identify which exploits may be effective or to adjust its behavior based on software versions present on the target machine.
API: GetFileVersionInfoSize
Description: Determines the size of the version information for the specified file.
Usage by Malware: This function is typically called before GetFileVersionInfo to allocate sufficient buffer for storing version information, aiding in reconnaissance activities.
API: VerQueryValue
Description: Retrieves specific version information from the version-information resource.
Usage by Malware: This API is used to extract specific data from the version information, such as company name, file description, or original filename, which can be used for further targeting or impersonation tactics.

iphlpapi.dll

Description: iphlpapi.dll handles IP Helper API functions, which assist in retrieving and manipulating network configuration settings, including IP addresses, network interfaces, and other TCP/IP settings.
Usage by Malware: This DLL allows malware to scan the network configuration of the infected machine, facilitating network mapping, identifying potential targets within the network, and optimizing its spread or data exfiltration strategies based on network setup.
API: GetAdaptersInfo
Description: Retrieves information about the network adapters on the local computer.
Usage by Malware: Malware uses this function to gather network adapter information, which can include IP address, mask, and gateway, useful for network mapping or planning further lateral movements.
API: GetIpNetTable
Description: Retrieves the IP-to-physical address mapping table.
Usage by Malware: This API helps malware identify all active machines on the local network by mapping IP addresses to physical addresses (MAC), useful for spreading to other machines or for network surveillance.
API: GetIfTable
Description: Retrieves information about the network interface controllers on the local system.
Usage by Malware: Malware can use this to determine active interfaces, their states, and properties, which assists in selecting interfaces for sending or receiving data, or for traffic interception and manipulation.
API: IcmpSendEcho
Description: Sends an ICMP Echo request and retrieves the Echo response to check the reachability of a host.
Usage by Malware: This function can be used for network reconnaissance, checking the availability of other systems on the network, which might be targets for infection or data exfiltration paths.
API: GetNetworkParams
Description: Retrieves network parameters for the local computer, including the domain name and DNS server addresses.
Usage by Malware: Malware can use this API to understand the network configuration, identify primary DNS servers (potentially for DNS poisoning attacks), or adjust its communication strategy to blend in with normal traffic.
API: GetTcpTable
Description: Retrieves the table of active TCP connections.
Usage by Malware: This function allows malware to scan active TCP connections on a system, identifying open ports and established connections that can be hijacked or disrupted.
API: GetUdpTable
Description: Retrieves the table of active UDP connections.
Usage by Malware: Useful for identifying active UDP services which might be vulnerable to exploitation or useful for data exfiltration without establishing a reliable connection.
API: GetIpForwardTable
Description: Retrieves the IP forwarding table, which contains routes that packets may take.
Usage by Malware: This API helps malware understand the routing table of a host, which can be manipulated for redirecting traffic or for conducting man-in-the-middle attacks.
API: GetIpStatistics
Description: Retrieves IP statistics for the local computer.
Usage by Malware: Malware might use this to gather statistics about IP traffic, helping to identify heavily used protocols or services, or to detect security measures like firewalls based on packet rejections or errors.
API: GetIcmpStatistics
Description: Retrieves statistics for ICMP (Internet Control Message Protocol), such as the number of messages sent, received, and errors.
Usage by Malware: This information can be used to assess the network’s responsiveness and vulnerabilities to ICMP-based attacks like ping floods or smurf attacks.
API: SetIpTTL
Description: Sets the Time-To-Live (TTL) for IP packets sent from the local computer.
Usage by Malware: By manipulating TTL values, malware can control how far packets travel, which is useful for evading network monitoring tools that might be set to capture only local or regional traffic.
API: SendARP
Description: Sends an ARP (Address Resolution Protocol) request to obtain the physical address that corresponds to the specified IP address.
Usage by Malware: Used for ARP poisoning or spoofing, which allows malware to intercept, modify, or block traffic between two systems on a local network.

Security and Access Control

secur32.dll

Description: secur32.dll deals with security-related functions in Windows, providing access to Security Support Provider Interface (SSPI) which allows applications to use various security models available on a computer.
Usage by Malware: Malware often exploits secur32.dll for authenticating and impersonating users, accessing sensitive data, or bypassing security mechanisms by leveraging SSPI functionalities.
API: AcquireCredentialsHandle
Description: Acquires a handle to preexisting credentials of a security principal, which are used by the SSPI to authenticate the principal in a security context.
Usage by Malware: Malware uses this API to gain access to the credentials of legitimate users, enabling it to authenticate as those users and access restricted data or systems.
API: InitializeSecurityContext
Description: Initiates the client side, outbound security context from a credential handle.
Usage by Malware: This function allows malware to set up secure sessions impersonating a legitimate user, potentially to access network resources or initiate secure communications under false pretenses.
API: AcceptSecurityContext
Description: Enables the server component of a transport application to establish a security context between the server and a remote client.
Usage by Malware: Malware on a server can use this to accept incoming secure connection requests, facilitating data theft or spreading across a network.
API: DeleteSecurityContext
Description: Deletes the security context associated with an authenticated session.
Usage by Malware: Malware can use this API to clean up after itself, removing traces of the security contexts it created to avoid detection and analysis.
API: QuerySecurityPackageInfo
Description: Retrieves information about the security packages available on the system.
Usage by Malware: This function allows malware to gather intelligence on the security mechanisms in place, enabling it to tailor its attack strategies to the specific security configurations it encounters.
API: EnumerateSecurityPackages
Description: Provides a list of security packages supported on a system.
Usage by Malware: Malware can use this API to determine which security protocols are available, potentially identifying weaker or less commonly used packages that may be easier to exploit.
API: ImpersonateSecurityContext
Description: Allows an application to impersonate a security context, which may be necessary for accessing resources or performing operations on behalf of the user associated with the context.
Usage by Malware: This API is crucial for malware that needs to operate under the guise of another user, particularly for accessing files, settings, or network resources that are otherwise restricted.

schannel.dll

Description: schannel.dll is involved with the Secure Channel (Schannel) security package that implements protocols such as SSL and TLS for encrypted communications.
Usage by Malware: By exploiting schannel.dll, malware can intercept or manipulate secure communications, decrypt SSL/TLS sessions, or create its own encrypted connections to external servers for secure data exfiltration.
API: AcquireCredentialsHandle (also used in secur32.dll)
Description: Acquires a handle to the credentials needed for building a security context with Schannel security package.
Usage by Malware: Malware uses this to establish encrypted channels, masquerading as legitimate software to communicate securely with command and control servers.
API: InitializeSecurityContext (also used in secur32.dll)
Description: In the context of Schannel, this is used to build a security context that can be used for setting up SSL/TLS connections.
Usage by Malware: Useful for malware when initiating encrypted communications, ensuring that data exfiltration or command transmissions are secured against eavesdropping.
API: EncryptMessage
Description: Encrypts a message in the context of the established security context.
Usage by Malware: Malware may use this API to encrypt data before exfiltration, ensuring that intercepted communications are difficult to decipher.
API: DecryptMessage
Description: Decrypts a message that was encrypted using the EncryptMessage function.
Usage by Malware: This can be used by malware to decrypt incoming commands or data from its controllers, maintaining a secure two-way communication channel.
API: FreeCredentialsHandle
Description: Frees a handle obtained by AcquireCredentialsHandle.
Usage by Malware: Proper cleanup of credentials by malware can help it avoid detection by making its activities less noticeable to system monitoring tools.
API: ApplyControlToken
Description: Applies a control token to a security context, such as breaking the connection.
Usage by Malware: This function can be used by malware to finely control SSL/TLS connections, including abruptly terminating them to disrupt communications or evade security checks.
API: QueryContextAttributes
Description: Retrieves attributes of the security context, such as session keys or the sizes of cryptographic tokens.
Usage by Malware: Malware may use this API to obtain detailed information about encryption keys and algorithms in use, which could facilitate decryption of secured communications or impersonation attacks.
API: SetContextAttributes
Description: Modifies attributes in a security context, like changing the way a session validates certificates.
Usage by Malware: Adjusting context attributes can allow malware to bypass certain encryption or security checks, making its network activities less detectable.

Miscellaneous

oleaut32.dll

Description: oleaut32.dll supports Object Linking and Embedding (OLE) Automation, facilitating the distribution and management of automation objects from different applications.
Usage by Malware: Malware utilizes oleaut32.dll for automating the execution of scripts or embedding malicious objects within documents that when opened, execute the malware. This is particularly common in attacks involving Office documents.
API: CreateObject
Description: Creates an instance of a COM object based on its class identifier (CLSID).
Usage by Malware: Malware can use this API to instantiate COM objects, including those that might be used to execute malicious code or perform other harmful actions.
API: SafeArrayCreate
Description: Creates a new array descriptor, allocates memory for the array data, and returns a pointer to the array descriptor.
Usage by Malware: Malware may use this API to create arrays for storing data or parameters used in its malicious operations, such as data to be transmitted over a network or arguments for function calls.
API: SysAllocString
Description: Allocates a new string, copies the passed string into the allocated memory, and returns a pointer to the new string.
Usage by Malware: Malware can use this API to allocate memory for strings, particularly when constructing payloads or crafting messages for communication with remote servers or other components.
API: VariantInit
Description: Initializes a VARIANT data type.
Usage by Malware: Malware may use this API to initialize VARIANT variables before using them to store data or parameters for COM function calls.
API: DispCallFunc
Description: Calls a method on an object that supports IDispatch.
Usage by Malware: Malware can use this API to invoke methods on COM objects, including those that may contain malicious code or provide access to system resources.

ole32.dll

Description: ole32.dll provides core OLE (Object Linking and Embedding) functions, enabling applications to create compound documents and link or embed data from different programs.
Usage by Malware: This DLL is crucial for malware that needs to manipulate compound documents, such as embedding malicious code in files that are likely to be shared and opened by other users, facilitating the spread of the malware across different systems.
API: CoCreateInstance
Description: Creates a new instance of a specified class on a specified machine.
Usage by Malware: Malware can use this API to instantiate COM objects, including those that may contain malicious code or provide access to system resources.
API: OleInitialize
Description: Initializes the COM library on the current thread.
Usage by Malware: Malware may call this API to initialize COM, enabling it to interact with COM objects and utilize various COM-related functionalities.
API: OleLoadFromStream
Description: Loads an object from a stream.
Usage by Malware: Malware can use this API to load objects embedded within documents or other files, potentially including malicious payloads or code.
API: OleCreateFromData
Description: Creates an embedded object from data contained in a data object.
Usage by Malware: Malware can use this API to create embedded objects within documents, potentially including malicious payloads or code.
API: OleSetClipboard
Description: Places data on the clipboard in a specified data format.
Usage by Malware: Malware may use this API to place malicious data on the clipboard, potentially enabling further propagation or execution when users paste the content into other documents or applications.
API: OleSaveToStream
Description: Saves an object and all its associated data to the specified stream.
Usage by Malware: Malware can use this API to save objects, potentially including malicious payloads or code, to streams within documents or other files.

This list includes some of the most commonly used DLLs in malware for specific tasks, ranging from network communications and file manipulation to more complex system interactions. Each DLL has a set of functionalities that can be exploited by malware to achieve its goals.

Imagine you’re a detective investigating two different crime scenes. At one scene, you’re examining a book that might contain clues. At the other scene, you’re looking through a collection of notes left behind by someone involved in the crime.

Analyzing a Binary:

When analyzing a binary file, we typically examine the file itself using tools like “strings” to extract readable ASCII and Unicode strings. These strings may include function names, API calls, file paths, or other human-readable data embedded within the binary.
We look for specific API calls, such as those listed in the example, and associated data or parameters within the binary file. This helps us understand the behavior of the malware and its intended functionality without executing the binary.

Analyzing a Dumped Process:

When analyzing a dumped process, we are working with a memory dump captured from a running process. This dump contains the state of the process at the time it was captured, including its memory contents, such as loaded modules, function calls, and data structures.
We apply similar techniques, such as using “strings” to extract readable strings from the memory dump. However, the context is different because we’re analyzing the runtime state of a process rather than a standalone binary file.
The strings we extract from the dumped process may include API calls, function names, parameters, and other data relevant to the process’s execution.

So, in both cases, you’re using similar techniques—reading through written materials—to gather information. However, the context is different because you’re dealing with different types of evidence: a book in one case and notes in the other. Similarly, when we analyze binaries and dumped processes, we’re using similar tools and methods, but the context of what we’re examining—the binary file versus the memory dump—makes the approach slightly different.

Tools that can be used

VirusTotal

Description: VirusTotal is a popular online service that analyzes files and URLs through dozens of antivirus engines and website scanners. It provides a comprehensive report on detected threats and unusual behaviors.
Usage: You can upload a suspicious file or submit a URL to VirusTotal, and it will scan it using various antivirus engines, offering a quick way to see if the file is recognized as malicious by multiple security vendors.

VirusTotal CLI

Description: VirusTotal offers a command-line interface (CLI) that allows users to upload and check files against its database using various antivirus engines directly from a Linux terminal.
Usage: The tool is used for uploading suspicious files to the VirusTotal website via CLI, providing a comprehensive analysis report based on multiple security vendors.

Binwalk

Description: Binwalk is a tool for analyzing and extracting firmware images and executable files. It is particularly useful for identifying embedded files and executable code within larger binary files.
Usage: It can be used to scan a binary for embedded files and executable code, helping to identify hidden payloads that could be malicious.

strings

Description: strings is a simple tool included in most Unix-like systems that extracts human-readable strings from binary files, which can reveal insights about what the binary might be doing.
Usage: Useful for spotting suspicious URLs, file paths, or other indicators of malicious activity hidden within the binary.

Objdump

Description: Objdump is a versatile tool part of the GNU Binutils package for displaying information about one or more binary files. It supports various formats and is used extensively for examining the contents of executables and object files.
Usage: Objdump is employed to disassemble binaries, show information about headers, and view the contents of sections within the binary. While it is widely used for disassembly, it can also provide valuable insights into the structure and behavior of executable files without executing them, making it an essential tool for static analysis.

Identifying Malicious Activity with Strings

Imagine you have a magic wand that can pull out hidden messages from a tangled web of words. Well, that’s sort of what “strings” does in the world of computers. You see, when you look at a computer program, it’s like peering into a dense forest of ones and zeros. It’s pretty confusing! But buried within all those binary digits are little pockets of human-readable text—words, phrases, and sometimes even secret codes.

Now, “strings” is like that magic wand I mentioned earlier. It sweeps through all those ones and zeros and plucks out any words or sentences it finds. It’s like shining a flashlight in a dark room to see what’s hiding in the shadows. But why do we care about these strings? Well, in the world of cybersecurity, bad guys often hide their mischievous plans within these strings. They might stash secret commands, sneaky URLs, or even incriminating messages that could give away their intentions.

So, when we’re trying to figure out if a program is up to no good, we use “strings” to reveal its secrets. We pull out those hidden messages and scrutinize them closely, looking for clues that might hint at something malicious lurking within the code. It’s like detective work for computers—sifting through clues, unraveling mysteries, and ultimately shining a light on the shady activities of cybercriminals. And “strings” is one of our trusty tools in the toolkit, helping us decipher the cryptic language of malware and keep our digital world safe from harm.

When it comes to analyzing malware, understanding the secrets hidden within its code is crucial. “Strings” is a powerful tool that helps uncover these secrets, whether we’re dealing with a standalone malicious binary or a running process on a computer.

When we analyze a malicious binary using “strings,” we’re essentially peeling back the layers of its code to reveal any human-readable text buried within. This could include things like suspicious URLs, commands, or even messages left by the malware authors. By running “strings” on the binary, we extract these text snippets and examine them closely for any signs of malicious activity.

Now, when we’re dealing with a running process, the approach is a bit different. Instead of analyzing a static file, we’re looking at the memory of a live program as it’s actively running on the system. This means we can’t simply run “strings” on a process like we would with a binary file. Instead, we use specialized tools and techniques to extract strings from the process’s memory.

These memory-resident strings can be just as revealing as those found in a static binary. They might contain URLs that the malware is trying to connect to, commands it’s receiving from a remote server, or even sensitive information it’s trying to steal. By analyzing these strings in the context of a live process, we can gain valuable insights into the malware’s behavior and intentions.

So whether we’re dissecting a dormant binary or examining a live process, “strings” remains a valuable ally in the fight against malware. It helps us uncover the hidden messages and secrets lurking within, allowing us to better understand, detect, and defend against cyber threats.

Using Strings for Analysis

Extract Strings and Save to File:

Command: strings suspicious_binary | tee malicious_file.txt
Description: This command extracts readable strings from the binary and saves them to malicious_file.txt, allowing for real-time observation in the terminal as well. This file serves as a basis for further analysis, containing potential clues about the binary’s functionality or hidden data.

Search for IP Addresses:

Command: grep -E -o ‘([0-9]{1,3}\.){3}[0-9]{1,3}’ malicious_file.txt > ip_addresses.txt
Description: Use regular expressions to filter and isolate IP addresses from malicious_file.txt, saving the results in ip_addresses.txt. This helps in identifying network-related activities or hardcoded server addresses that could be linked to malicious operations.

Search for URLs:

Command: grep -E -o ‘https?://[^[:space:]]+’ malicious_file.txt > urls.txt
Description: Extract URLs from the dumped strings file, directing the findings to urls.txt. This can reveal command and control servers, phishing links, or other malicious URLs embedded within the binary.

Search for Registry Keys:

Command: grep -E -o ‘HKEY_[A-Za-z0-9_/]+’ malicious_file.txt > registry_keys.txt
Description: Identify any Windows registry keys referenced within the strings, saving them to registry_keys.txt. This is particularly useful for uncovering potential registry manipulations or configurations that malware might use to achieve persistence or launch malicious payloads at system startup.

Adjust Regular Expressions for Specific Needs:

Description: The regular expressions used in the grep commands can be adjusted to refine the search criteria or to match specific patterns relevant to the investigation. This flexibility allows for targeted analysis tailored to the particular attributes of the suspected malware.

By systematically applying these techniques using the strings tool, analysts can effectively sift through a binary to uncover hidden data and potential indicators of malicious intent. This process is crucial for preliminary investigations and helps to prepare the groundwork for more detailed forensic analysis.

Identifying Malicious Activity with Objdump

Imagine you’re a detective in a classic film noir. Your case? A mysterious, sealed box with layers of intricate locks. But instead of picking each lock by hand, you have a master key that reveals what’s inside instantly. That’s what “objdump” does in the cyber world.

“Objdump” is a powerful tool that lets us peek inside the “box” of executable files, also known as binaries. These files are like the sealed boxes of the digital realm, full of code that tells a computer what to do. But to us, they just look like a jumble of confusing symbols and numbers. That’s where “objdump” comes in. It’s like our master key, unlocking the binaries to show us their contents in a way we can understand.

Now, why is this important? In cybersecurity, the bad guys—hackers, malware creators, and other digital miscreants—often use these executable files to carry out their schemes. They might hide malicious instructions, or booby traps waiting to spring on unsuspecting users. By using “objdump,” we can take these binaries apart to see exactly what they’re made of and what they’re programmed to do.

When we analyze a suspicious binary with “objdump,” we’re conducting a thorough examination. We can see the assembly language—the basic instructions that the computer reads to execute the program. This can show us hidden commands or unusual patterns that suggest the file might be up to no good.

When you’re using objdump to identify malicious activity within binaries, it’s like being an archeologist meticulously examining artifacts to understand ancient civilizations. Except, in this case, you’re analyzing binary files to uncover hidden malicious intents. Here’s a guide on what to look for and how to use objdump to detect these potential threats.

What to Look For:

Unusual Entry Points: Normally, the entry point of a program should be the starting point of the main function or a standard initialization routine. Malware might modify this to execute malicious code first.
Suspicious Function Calls: Look for calls to risky functions, especially those that interact with the network, file system, or execute commands. Functions like system(), exec(), or ShellExecute() in unexpected locations might be suspicious.
Embedded Binary or Hexadecimal Data: Malware might contain embedded payloads encoded in binary or hex. These can sometimes appear as large arrays or unusual data segments within the code.
References to Anti-Debugging or Obfuscation Techniques: Check for the presence of anti-debugging calls or obfuscation techniques. This might include calls to functions like IsDebuggerPresent(), or code that manipulates flags and handlers to deter debugging.
Strange or Obfuscated Strings: Strings in binaries can reveal a lot about their functionality. Look for obfuscated or encoded strings that could be hiding URLs, file paths, or other commands.
Irregular Section Names or Properties: Malicious files may have unusual section names or sections with unexpected properties, such as writable and executable permissions combined, which is generally a red flag.

Using Objdump to Analyze Malicious Activities:

Disassemble to Check for Entry Points and Function Calls:

Command: objdump -d suspicious_binary > disassembly.txt
Description: Disassemble the binary to view assembly code, particularly useful for inspecting the entry point and searching for calls to suspicious functions. The output is directed to disassembly.txt for detailed analysis.

Inspect Headers for Anomalies:

Command: objdump -x suspicious_binary > headers.txt
Description: This command inspects all headers of the binary, outputting the details to headers.txt. Review this file for unusual section properties or headers that deviate from typical executable patterns, such as sections with both write and execute permissions, which are uncommon and potentially dangerous.

List Strings to Find Embedded Data and Obfuscated Strings:

Command: strings -t x suspicious_binary > strings.txt
Description: Extract readable strings from the binary, along with their offsets in the file (-t x), saving the results in strings.txt. This file can then be searched for patterns that indicate obfuscated data or suspicious strings, providing clues about the binary’s behavior or intent.

Symbol Table Analysis:

Command: objdump -t suspicious_binary > symbols.txt
Description: Generate a list of all symbols from the binary, saving it in symbols.txt. Analyze this file for unexpected symbols or modifications to standard library functions, which could suggest malicious alterations or the presence of hooks.

Analyze for Embedded Payloads:

Command: objdump -s suspicious_binary > sections.txt
Description: Dump all the section data of the binary into sections.txt. Review this file to identify sections filled with binary or hexadecimal values that appear out of place. Such data could be embedded payloads designed to execute malicious activities.

Each step in this process utilizes objdump to reveal different aspects of the binary file, helping analysts to uncover hidden malicious functionalities efficiently. By methodically applying these commands, you can gain deep insights into the structure and potential threats posed by suspicious binaries without executing them, ensuring a safe and thorough analysis.

By using objdump with these commands and keeping an eye out for these indicators, you can effectively scrutinize binary files for signs of malicious activity, much like a detective putting together pieces of a puzzle to solve a case.

Identifying Malicious Activity with Binwalk

Imagine you’re an explorer with a high-tech X-ray machine that can see through solid objects to reveal the treasures or traps hidden within. That’s akin to what “Binwalk” does in the digital world. Binwalk is like this X-ray machine for firmware images and binary files, allowing us to peer inside and uncover the layers and secrets buried within.

Binwalk is a powerful tool designed for analyzing and extracting firmware, but it’s also immensely useful for dissecting any type of binary file. It scans through the binary data, identifying embedded files, executable code, and even potential areas where hidden data might reside.

But why is this important in cybersecurity? Well, in the hands of cybercriminals, binaries often contain hidden functionalities or malicious payloads that aren’t immediately apparent. They might include hidden backdoors, secret commands, or embedded malware components designed to execute harmful actions.

When we deploy Binwalk to analyze a suspicious binary, we’re essentially conducting an in-depth examination without ever executing the file. This allows us to uncover embedded malicious content that could have been activated had the binary been run in a live environment. It’s a crucial step in preemptive defense—stopping malware before it has a chance to act.

Using Binwalk for Malicious Activity Analysis:

Embedded File Detection:

Command: binwalk -e suspicious_binary
Description: This command extracts all identifiable embedded files and file systems from the binary, which can then be further analyzed using other tools. It’s particularly useful for uncovering hidden content that may not be apparent through a simple inspection.

Signature Analysis:

Command: binwalk -B suspicious_binary
Description: Perform a signature scan on the binary to detect known file types and embedded data patterns. This helps identify components within the binary that align with known malware signatures or unexpected file types within the binary structure.

Entropy Analysis:

Command: binwalk –entropy all suspicious_binary
Description: Analyze the entropy of the binary to identify high entropy areas which might indicate encryption, compression, or obfuscation. High entropy is often a hallmark of efforts to conceal malicious code within seemingly benign binaries.

Extract Specific Sections for Detailed Analysis:

Command: binwalk -W suspicious_binary
Description: This command can be used to examine specific sections of the binary in detail. It helps in analyzing the content of each section, looking for anomalies or irregular patterns that might suggest manipulation or embedded malicious elements.

Automated Extraction and Analysis:

Command: binwalk -Me suspicious_binary
Description: Automatically extract and recursively scan extracted files. This is particularly useful for deeply nested binary structures where manual extraction might miss embedded layers. It streamlines the process of peeling back layers of an encapsulated file or firmware image.

Scenario Analysis with Binwalk:

Let’s say you’ve obtained a firmware image or a binary file suspected of containing malware. You would use Binwalk to peel back the layers of the file, much like an archeologist carefully excavating a site to find hidden artifacts.

By analyzing the extracted and identified components with Binwalk, you could uncover not only the standard operational features of the binary but also any malicious or anomalous elements hidden within. This includes checking for unexpected file types, compressed payloads, or encrypted data that doesn’t belong in a typical binary or firmware image.

These findings could lead to deeper investigations, such as analyzing the extracted payloads with antivirus tools, studying obfuscated code to reveal its true nature, or even running the components in a controlled environment to observe their behavior.

Thus, whether we’re dissecting a dormant binary or examining the components of a complex firmware, Binwalk remains an invaluable ally in the fight against malware. It helps us uncover the hidden layers and secrets embedded within binaries, allowing us to better understand, detect, and defend against cyber threats.

Examples of What You May Find

Here are some common things to look for along with potential malicious values.

CreateProcess:

We search for occurrences of “CreateProcess” along with any accompanying parameters or data.
For example, we might find a string like: CreateProcessA(“malicious.exe”, NULL, …).

LoadLibrary:

We look for strings containing “LoadLibrary” and any DLL file names.
For instance, we might spot: LoadLibrary(“evil.dll”).

WriteFile:

We search for strings indicating file operations, such as “WriteFile”.
We might discover: WriteFile(hFile, buffer, size, …).

RegSetValue:

We scan for strings suggesting registry manipulation, like “RegSetValue”.
We might encounter: RegSetValue(HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run, “Malware”, “malicious.exe”).

InternetOpen:

We look for occurrences of “InternetOpen” and potential URLs or connection settings.
We could find: InternetOpen(“MalwareAgent”, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0).

HttpSendRequest:

We identify instances of “HttpSendRequest” and inspect any accompanying data.
We might come across: HttpSendRequest(hRequest, headers, …).

CreateThread:

We look for “CreateThread” and any parameters.
We might spot: CreateThread(NULL, 0, maliciousFunction, NULL, 0, NULL).

FindWindow:

We seek occurrences of “FindWindow” and associated window names.
For instance, we might find: FindWindow(“MalwareWindow”, NULL).

EnumerateProcesses:

We search for “EnumerateProcesses” and examine any related data.
We might discover: EnumerateProcesses(ProcessList, sizeof(ProcessList)).

GetProcAddress:

We search for “GetProcAddress” and any DLL or function names.
We might find: GetProcAddress(GetModuleHandle(“kernel32.dll”), “CreateFileA”).

Static Malware Analysis

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