Windows XP service pack 3 (all updates and patches installed), NIS 2010 Version 17.5.0.127. Computer regularly
scanned with no problems found. This computer is my network server (7 other machines attached, all XP, NIS 2010 protected).
At irregular intervals a number of different error messages appear on screen relating to emails. These do not appear to be anything legimate as from, to and subject fields are loaded with odd characters. These error messages can number in the hundreds and eventually the server will cause the other computers to slow down and stop. I usually end up having to restart the computer. (error message 500 5.0.0. service unavailable as an example) I have a screen dump of the message for forwarding.
The question is do I have a Trojan on my server and am I sending these emails? I have checked msconfig, startup and the process list but all appears to be ok. At present I am considering the dreaded re-format and re-installation which I am not looking forward to.