Your description is not exactly complete.
The following could also be a virus, depending on where and what it is:
system32 - system32.exe - Process Information
Process File: system32 or system32.exe
Process Name: MARI Virus
system32.exe is a process which is registered as the MARI Virus Trojan. This Trojan allows attackers to access your computer from remote locations, stealing passwords, Internet banking and personal data. This process is a security risk and should be removed from your system. Please see additional details regarding this process.
I suggest you run the following free scan from Microsoft.
It will clean your system even if it isn't infected so it is worthwhile to do.
Windows One Care Free Scan
Go to Windows Live Onecare Free Scan
It will say "Get a free PC safety scan"http://safety.live.com/site/en-us/default.htm
Make sure you click "Full Service Scan"
in the middle of the page and not the "Try It Now Free" on the right side.
Allow it to download an Active X component.
Choose "Complete Scan" in the window that opens
Do not click on anything else that offers you a free trial or to sign up if you live in the US.
Allow it to scan - it may take quite a while, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.