ISC2 Systems Security Certified Practitioner (SSCP) Practice Question

Impersonation callers often rely on urgency to bypass normal verification. The most effective and minimally disruptive countermeasure is to validate the caller's identity through an independent channel that the attacker cannot control. Hanging up and placing a return call to the phone number already recorded in the corporate directory (or obtained from HR records) uses information established before the incident and does not rely on data supplied by the caller. This confirms the individual's legitimacy before any privileged action-such as resetting MFA-occurs. Simply complying with the request, emailing credentials, or giving a one-time code over the same call all leave the technician vulnerable to a convincing impostor. Escalating directly to AWS Support does not address identity verification and delays resolution without actually preventing impersonation. Therefore, performing an out-of-band callback to a trusted number is the correct first response.