How do anti-virus products work?

Anti-virus products primarily function by scanning files and comparing their code against a database of known malware signatures, often referred to as a virus dictionary. This signature-based detection method works by identifying specific patterns or characteristics of malicious software. When a file is accessed or executed, the anti-virus program checks it against the stored signatures; if a match is found, the file is flagged as potentially harmful.

This approach is effective against known threats, as it can quickly identify and neutralize files that exhibit signatures of malware that have been documented and cataloged. While this method is foundational in anti-virus technology, it's important to note that it may not be sufficient to detect new or modified viruses that have not yet been added to the database. This is where other methodologies, such as behavioral detection or heuristic analysis, become relevant in comprehensive anti-virus solutions. However, the given answer highlights the core mechanism of how many traditional anti-virus products operate, which is by recognizing specific malicious code patterns.