Spambot hijack that Symantec and MBAM won't detect

One of my users ran a fedex type email attachment from her home email. (She can't find the email to let me look at it.)

Anyway the Symantec firewall keeps going crazy with undeliverable type email warnings for emails that she didn't send. So I ran a full scan with Symantec and it came up with nothing. I then ran MBAM full scan and nothing. Nothing out of the ordinary in the Windows/RUN registry either.

Does anyone know what this thing is?

Thanks!
Zed