Dhcpclient.exe is a worm W32.Toxbot.C. Dhcpclient.exe opens a back door on IRC channel. Dhcpclient.exe monitors user Internet activity and private information. It sends stolen data to a hacker site. Related files: %System%\dhcpclient.exe Adds the value: "(Default)" = "Service" "Start" = "2" "ImagePath" = "%System%\dhcpclient.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill dhcpclient.exe process and remove dhcpclient.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.