An indicator of compromise (IOC) is a piece of evidence that suggests that an information system or network has been compromised or is at risk of being compromised. This could include suspicious activity or behavior, changes in system configurations, or other anomalies that suggest the presence of malicious activity.
There are many different types of IOCs that can be used to detect and identify potential threats to a system or network. Some examples include:
Malware: Malware, or malicious software, is a type of IOC that is used to infect a system or network with malicious code. This could include viruses, worms, trojans, or other types of malware that are designed to compromise the security of a system or network.
Network traffic: Network traffic is another type of IOC that can be used to identify potential threats. This could include unusual traffic patterns, such as large amounts of data being transferred between two systems, or strange connections to external servers.
System logs: System logs are a valuable resource for identifying IOCs because they record all activity on a system or network. This could include logins, file access, and other system events that could be indicative of malicious activity.
File changes: Changes to system or network files can also be an IOC. For example, if a system administrator notices that a critical system file has been modified without their knowledge, this could be an indication of a compromise.
User behavior: User behavior is another type of IOC that can be used to identify potential threats. This could include unusual logins, access to sensitive data, or other unusual activities that might suggest malicious intent.
Overall, IOCs are an important tool for detecting and responding to potential security threats. By monitoring for these indicators, organizations can take proactive steps to protect their systems and networks from compromise.