A few days ago, I noticed that our Windows Server 2003 system has strange scheduled tasks. I do not know where they came from or who set them up. I deleted them and they came up again today. They have names such as "At1","At2", "At3" and the status says that they are running.
When I open their properties, the run command looks like rundll32.exe zfypspqu.u,ygxjgq
.
What it could be? Does my server have some virus? I did a scan with nod32 and it didn't report anything. I do not have anything unusual set up on this server - it's only running SQLServer 2005 with ReportServer. Two other servers with similar configuration do not have these strange scheduled tasks.
That's a Conficker infection.
Basic steps to remove it:
If you have multiple systems, make sure you fix them all.
The full Microsoft guide for protecting yourself from Conficker is here.
Good luck, I've had to deal with a Conficker infection at a smallish client, about 30 servers spread throughout 12 sites, it was not fun.
Try to scan, disinfect, apply patch for all computers in your network at the same time if possible, had bad experience with it (B version, our network has around 300 computers in 3 sites)
http://www.confickerworkinggroup.org
http://www.confickerworkinggroup.org/wiki/pmwiki.php/ENT/Enterprise#toc10
I update batch file to apply for GPO (got it somewhere on Internet)