What are signatures as they relate to security threats?

[JefferyPulido]

Signatures detect known attack behavior using predefined patterns.

[Danny_williamson]

A signature is a unique identifier of malware or exploit activities. Security tools match incoming traffic against these patterns to instantly block recognized threats like viruses, ransomware, or scan attempts.

[damonchastain]

Intrusion detection systems use signature databases to compare system activity with known malicious indicators. This improves accuracy for familiar threats but doesn’t detect brand-new zero-day attacks.