In biology, antigen is a foreign substance in the body that stimulates the production of an antibody, which in turn fights diseases. It is supposed to be good for you. Getting a particular antigen spam email, though, is probably just going to ruin your day.

Antigenis also the name of an antivirus software for Lotus Domino and Microsoft Exchange. As such, it scans email messages and attachments for possible malicious activities.
TROJ_DLOADER.EXI‘s author then is probably being ironic or funny because this malware arrives as an attachment to a spammed email that purports to be an automated message from the
“Antigen Quarantine area”about a scanned image file. See a sample below:

This Trojan downloads a spyware detected by Trend Micro as TSPY_BZUB.EQ from the Web page
http://www.{BLOCKED}den21.net.