What defines the activity of comparing observed events to known signatures?

The activity of comparing observed events to known signatures is defined as Signature-based Detection. This method relies on predefined patterns or signatures of known threats, such as viruses, malware, or unauthorized access attempts. Signature-based Detection works by monitoring the network or device for specific, recognizable signatures that match those in its database. When a match is found, an alert can be triggered, allowing for a prompt response to a potential security threat.

This approach is highly effective against established threats because it can quickly identify known malicious activities. However, it has limitations in detecting new or unknown threats that do not yet have signatures defined in the database. Thus, while useful for rapid detection of known issues, it necessitates regular updates and cannot address every potential vulnerability that might arise from novel or evolving threats.