Liam, a senior incident responder at a manufacturing company, is alerted to an email campaign...

Comprehensive and Detailed Explanation (ECIH-aligned):

This scenario clearly aligns with the eradication phase of the ECIH malware incident handling lifecycle. After detection and containment, eradication focuses on completely removing malicious artifacts and ensuring the threat cannot re-emerge.

Option D is correct because Liam’s actions—malware removal, account disabling, system restoration, and IOC documentation—are all aimed at fully eliminating the malware and attacker footholds. ECIH emphasizes that eradication must address malware binaries, persistence mechanisms, compromised credentials, and residual indicators.

Option B (forensic preservation) would avoid system changes, which Liam does not do. Option A is a training activity unrelated to response. Option C is infrastructure improvement, not incident handling.

ECIH explicitly states that failure to eradicate all traces often leads to reinfection or continued attacker access. Liam’s comprehensive approach ensures the environment is returned to a trusted state and prepares detection systems for future prevention.