A containment review is a rapid security check performed after a suspected incident, public claim, or unusual alert. Its goal is to limit possible spread and confirm which accounts, hosts, and services may be exposed. Teams use it to decide whether to isolate systems, reset credentials, block suspicious access, or keep monitoring while evidence is gathered.
This matters because early incident reports are often incomplete. A ransomware listing, for example, may be a real compromise, a partial intrusion, or only a claim. A containment review helps defenders avoid both extremes: overreacting without evidence or waiting too long while an attacker moves laterally. In practice, it focuses on recent logins, privilege changes, file access, endpoint alerts, and signs of persistence. The result is a clearer picture of scope and the first actions needed to reduce risk.