The organization remains in the eradication phase because malicious artifacts are still being removed from affected systems and the environment has not yet reached a trusted state suitable for complete restoration. The phrase “removing malware from some of the affected hosts” indicates that responders are actively eliminating the threat across the compromised estate rather than merely observing or documenting it.
Eradication addresses malware, attacker persistence, exploited vulnerabilities, unauthorized accounts, malicious configurations, compromised credentials, and other mechanisms that could permit reinfection or renewed access. Only after responders have sufficiently eliminated those causes should affected resources progress fully into recovery and return to normal operation. NIST's current incident-response model identifies containment, eradication, and recovery as related but distinct activities and emphasizes restoring assets only after appropriate incident handling has occurred.
Detection would have occurred when the incident was initially discovered. Analysis determines scope, cause, and impact. Preparation takes place before incidents by establishing plans, tools, procedures, and capabilities. Post-incident activities occur after response and restoration and focus on organizational improvement.
The two-week duration does not determine the phase. The activity being performed does : continued removal of malware indicates eradication.
Study Guide Reference: Incident Response and Management → Containment → Eradication → Malware Removal → Persistence Removal → System Validation → Recovery.
