Sifxinst.exe is a Trojan.Download.Chekin. Sifxinst.exe monitors user Internet activity and private information. It sends stolen data to a hacker site. Related files: Ttps.exe Sifxinst.exe Sbsrch_v22.dll %System%\Sysreg.exe %System%\OWMngr.exe Adds the value: "Sysreg"="%System%\Sysreg.exe" "OWMngr"="%System%\OWMngr.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill Sifxinst.exe process and remove Sifxinst.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.