What is the primary function of a signature based scanner?

The primary function of a signature-based scanner is to compare files against a library of signatures. In the context of cybersecurity, signatures are unique patterns or characteristics found in malware, viruses, or other malicious code. This scanner works by checking files against these predefined signatures to identify known threats.

When a file is scanned, the system looks for an exact match or a recognizable pattern that corresponds to an entry in the signature database. If a match is found, the scanner can classify the file as potentially harmful and take appropriate action, such as quarantining or deleting the file.

Other functions mentioned in the options, such as monitoring for unusual system activity or analyzing CPU utilization, describe different types of security mechanisms, such as behavior-based detection systems, which look for atypical patterns of operation rather than relying solely on known signatures. The detection of unauthorized user permissions also falls under access control and privilege management rather than being a focus of signature-based scanning. Thus, the role of a signature-based scanner is distinct and specifically focused on the identification of known malware through established signatures.