W32.Sasser Removal Tool

download the removal tool from:

http://www.symantec.com/content/en/us/global/removal_tool/threat_writeups/FxSasser.exe

follow the instruction on this symantec page

http://www.symantec.com/security_response/writeup.jsp?docid=2004-050114-1706-99

One more thing to note, disconnect the net connection if any and also disable any anti virus program including symantec’s own antivirus as some time theis removal tool is detected as worm-virus.