A. Evaluate the intrusion detection system alerts to determine the threat source and attack surface.

B. Communicate with employees to determine who opened the link and isolate the affected assets.

C. Examine the firewall and HIPS configuration to identify the exploited vulnerabilities and apply recommended mitigation.

D. Review the mail server and proxy logs to identify the impact of a potential breach.

E. Check the email header to identify the sender and analyze the link in an isolated environment.