An anti-virus scanner that matches files against a library of known malware is known as what type of scanner?

The correct choice for the type of anti-virus scanner that matches files against a library of known malware is known as signature-based scanning. This method operates by comparing files and software on a system to a database of predefined signatures, which are unique identifiers or patterns associated with known malware. When a file is scanned and a match is found in the signature database, the scanner can determine that the file is malicious.

Signature-based scanning is highly effective for detecting known threats because it relies on previously identified characteristics of malware. This method provides accuracy and fast detection, making it a staple in many anti-virus solutions. However, it does not recognize new or unknown malware that does not have a preexisting signature, which means it must be updated continuously with new signatures to remain effective against emerging threats.

In contrast, other scanning types, such as behavioral scanning, analyze the actions of programs running on the system to identify malicious behavior, rather than looking for known signatures. Anomaly-based scanning established deviations from the norm in system behavior to detect potential threats, while heuristic scanning uses algorithmic approaches to predict the likelihood of a file being malicious based on certain functionalities or characteristics. Each of these methods serves a distinct purpose in a layered security approach but does not specifically match files against a