Low threat Level,
Low damage capabilities,
Distinguishing charcteristscs:
The Subject of email varies ina predetermined list
The name of attachment varies with the .com, .exe, .scr, or .pif file
extension.
The size of attachment is consistant at 180,224 bytes

Details:

The W32.Mapson.C.Worm sends itself to all the contacts in the MSN
messenger contact list. As an added stealth device, the email may
spoof the From field.

This worm can spread itself through various files sharing programs
such as: KaZaA, KaZaA Lite, eDonkey2000, Gnucleus, Limewire,
Morpheus, and Grokster file-sharing networks, as well as through ICQ.

Finally, this worm terminates some popular antivirus, firewall, and
system-monitoring programs which allows for a blended threat.

Damage:

This worm compromises security settings by terminating various
programs such as antivirus software and firewalls.

For more informations see:
http://www.symantec.com/avcenter/venc/data/w32.mapson.c.worm.html