Merger, Acquisition, Forgotten Domain: How M&A Activity Quietly Expands Your Attack Surface

**M&A transactions create a high-risk window where forgotten domains, abandoned subdomains, unpatched legacy systems, and unmanaged cloud accounts are inherited and actively mapped by threat actors from announcement through integration; entity-first EASM and continuous monitoring are recommended to discover these unknown assets, prioritize day-one remediation, and prevent pre- and post-close compromises (illustrated by precedents such as the Verizon–Yahoo fallout).**