An Indicator of Compromise (IOC) is defined as a piece of information that can be used to identify the potential compromise of an environment: from a simple IP address to a set of tactics, techniques and procedures used by an attacker in a campaign. Although when we speak of IOC we always tend to think of indicators such as IP or domains, the concept goes beyond this, and depending on their granularity, we can find three types of indicators:
- Atomic indicators: those that cannot be broken down into smaller parts without losing their usefulness, such as an IP address or domain name.
- Calculated indicators: those derived from data involved in an incident, such as a hash of a file.
- Behavioral indicators: those that, from the treatment of the previous ones, allow the representation of the behavior of an attacker, his tactics, techniques and procedures (TTP).






