Breach parsers operate by ingesting data from various sources, including logs, network traffic captures, and threat intelligence feeds. They then apply advanced algorithms and machine learning techniques to parse this data, searching for known signatures of malicious activity, unusual behavior that may indicate a breach, and other relevant IOCs. The output of a breach parser typically includes detailed reports on the breach, such as the entry point of the attack, the methods used by the attackers, and the extent of the compromise.