A breach detection engine detects and mitigates the effects of breaches across one or more data sources. An index is generated based on one or more data sources and the index is queried using keywords indicative of potential breaches. A database of potential breaches is populated based on the query of the index. The potential breach database is queried using keywords associated with a system identity (e.g., a third party). A likelihood of a candidate breach is identified based on a set of breach criteria weights. A network node associated with a candidate breach determined to be an actual breach is identified for isolation or for the performance of one or more additional security actions.