What is a critical step in the Recovery phase of incident response?

The Recovery phase is a critical component of the incident response lifecycle, focusing on restoring systems and services to normal operation after a security incident has been contained and eradicated. The primary goal is to return affected systems to a known, secure, and trusted state. This involves actions such as restoring from clean backups, rebuilding systems from secure images, replacing compromised files, and applying necessary security patches to prevent re-infection. Ensuring the system is secure before it goes back online is paramount to prevent immediate re-compromise and to restore business confidence.

B. Ignoring incidents, even if they seem resolved, is negligent and can lead to recurrence or undiscovered persistence of the threat actor.

C. Deleting logs constitutes spoliation of evidence, which is often illegal and hinders post-incident analysis and future prevention efforts.

D. Preventing all user access indefinitely is not a recovery goal; the objective is to restore normal, secure business operations as quickly as possible.

1. National Institute of Standards and Technology (NIST). (2012). Special Publication 800-61 Rev. 2: Computer Security Incident Handling Guide. Section 3.3.4, "Recovery," p. 32. "After an incident has been successfully contained and the threat has been eradicated, the recovery phase begins... The primary goal of the recovery phase is to restore the affected systems and services to a secure and operational state."

2. Palo Alto Networks. (n.d.). What is Incident Response?. Palo Alto Networks Learning Center. "Recovery: After an incident is eradicated, the IR team helps return affected systems to business-as-usual operations. This can involve bringing systems back online, restoring data from backups, and continuing to monitor for any signs of lingering malicious activity."