Virus:Win32/Sirefef.J is a component of Win32/Sirefef - a multi-component family of malware that moderates an affected user's Internet experience by modifying search results, and generates pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components or performing the payload.
Virus:Win32/Sirefef.J is a detection for drivers that have been infected by Win32/Sirefef in order to download and execute files from specified Web sites.
A dropper component, detected as Trojandropper:win32/Sirefef.B
, overwrites an existing driver on the affected system. Overwritten driver files are detected as Virus:Win32/Sirefef variants.
Analysis by Scott Molenkamp
There are no obvious symptoms that indicate the presence of this malware on an affected computer.