How does URL reputation protect against malware links?

URL reputation databases track domains and pages associated with malware distribution. Email security systems check links against these databases, blocking or warning about known malicious destinations.

Reputation sources include: security vendor crawling and analysis, user reports, automated detection systems, and shared threat intelligence. When malware distribution is detected, URLs are flagged across participating systems.

Limitations: new URLs lack reputation history, compromised legitimate sites may not be flagged immediately, and sophisticated attackers use URL rotation to outrun databases. Reputation is one layer in multi-layered defense.