Joe, a User, Reports That Several of His Colleagues Have

Multiple Choice

Joe, a user, reports that several of his colleagues have received a suspicious email from his account that he did not send. A technician asks one of the colleagues to forward the email for inspection. After ruling out spoofing, the technician verifies the email originated from the corporate email server. Which of the following is the FIRST step the technician should take to correct this issue?

A) See if Joe's email address has been blacklisted
B) Change the password on Joe's email account
C) Update the antivirus and perform a full scan on the PC
D) Isolate Joe's computer from the network