We are using Windows XP for our client PCs and Windows 2003 R2 for the servers. Amongst others we have a file server and an Exchange 2003 Server. Here are the two problems I'm facing lately:
1. The file server freezes (and as a result all the clients that are using files that are located on that server freeze as well) every few days e.g. every week
I have scanned the server for viruses (using 2 different products) and all viruses have been cleaned (no viruses at the moment). I have also run extensive hardware diagnostic programs and all hardware appears to work fine.
2. Emails are being sent to users from themselves (sender and recipient the same) with spam content that have been blocked by our anti-spam software. Please note that open SMTP relaying has been blocked on the exchange server. The exchange server appears clean from viruses too.
Any suggestion with regards to any of the above is welcome. My question is this:
Could it be a virus causing both my problems? And If there is a virus causing it and it is located on the clients PCs (obviously not being detected by the AV software)
a) How do I find it?
b) How do I clean it? Especially if it is in a number of computers