Leak monitoring is the practice of tracking public or semi-public places where stolen-data claims are posted, copied, or aggregated. These sources can include extortion blogs, data-leak sites, paste-style dumps, forums, and automated threat-intelligence feeds that collect those posts. The goal is to notice when an organization appears in a claim or when its data is being advertised for sale or release.
In cyber security, leak monitoring matters because it gives defenders early warning that an intrusion may have moved into the extortion phase. It can help security teams validate reports, prioritize incident response, and search for exposed systems, stolen credentials, or backup failures. It is also useful for trend tracking, but it is not proof on its own: a listing may be duplicated, exaggerated, or unverified. For that reason, leak monitoring should be treated as an intelligence signal that supports investigation, not as a final verdict on breach scope or impact.