_c00EEE18.dat

Hello:
This computer is a Dell Dimension 4200 running XP Pro SP2, Symantec Antivirus Client. This is located in a small office, I am an IT consultant for them. There are security concerns at this location and I am only given access to computers at certain times of day for limited periods of time. No computers are allowed to be removed from the office, therefore I am unable to run the complete recommended spyware cleaning.
Symantec antivirus detects a Trojan at c:\Windows\System32\_c00EEEE18.dat. Symantec says it can't do anything with it, access is denied. Googling for this file gives no results. Neither does a search on Symantec's website.
I cannot delete, rename, or move this file in normal, Safe mode, nor command prompt.
I was able to delete it using Pocket Killbox.
So far things seem ok, but I'm concerned that removing this one file is too easy and that there must still be some remnants of the infection left.
Any suggestions?
Thanks.

 

I was able to run TrendMicro Housecall and it came back clean. The next time I'm able to access this computer I'll try running one or both of those scans as time permits.
thanks