IOCs, the CTI warhead
We have talked about IOCs in hashes, domain names, and IP addresses in almost all the previous chapters. You have probably grasped a bit of how they are used. This section provides more details to help you understand the concept in depth. IOCs are the pillars of actionable intelligence. They are evidence of abnormal behaviors in the system; hence, security monitoring revolves around observing the system for IOCs. Threat intelligence collected data contain IOCs – used to strengthen the organization's security posture. For example, internal data such as logs contain users' IP addresses, timestamps, accessed assets, usernames, and remote connection details, reflecting all internal activities. The external data contains adversaries, tactics, techniques, and procedures (TTPs), and IOCs, which the CTI team can use to protect the system.
IOCs are the starting point of threat intelligence analysis, forensics investigations, and incident processes...