Soooo... Max Reiner... what org did Kendall join that caused these problems?
I haven't seen any evidence in this thread that the problem was anything to do with Kendall's PC or email account.

Email addresses are harvested from the mailboxes of virus infected PCs. The addresses are fed into a botnet and the spam sent from a totally different location. The addresses could have come from anybody with whom Kendall has exchanged emails.

By far the most unlikely scenario is for the email account itself to have been hacked.