slsvc.exe - Windows Vista Software Licensing Service
Windows Vista includes a new subsystem, known as the "Software Licensing Service," which manages digital signatures and other factors related to software licensing. It makes use of a new process known as slsvc.exe. This process enables the download, installation and enforcement of digital licenses for Windows and Windows applications.This process cannot be terminated without compromising Windows Vista's functionality. If this process is not present, both Windows and any licensed applications may exhibit symptoms of reduced functionality. The exact set of behaviors exhibited under this "crippled" mode is not known, but a Microsoft Tech report notes that attempts to upgrade an installed package while slsvc.exe is not running will produce error messages from the "Software Licensing Commerce Client" and the upgrade will fail.
The legitimate copy of slsvc.exe should be located in the C:\windows\system32 directory. Copies found in other locations may represent malware of some type that has been installed on your PC. When running, the slsvc.exe process should appear under the SYSTEM user ID. One, and only one instance of this process should appear on a running PC.
This service does not exist under previous versions of Microsoft Windows. It should not be found on XP, 2000, and other early variants. If such a file exists on a non-Vista machine, it should be quarantined immediately and treated as a virus. No reports of malware using the slsvc.exe name have been received, but this situation could change at any time if malware authors choose to hijack the process name. This is a common practice, so the appearance of malware misusing this file name should be expected.
As always, if you suspect a malware infestation you should download and run a current copy of an antivirus/malware scanner in order to isolate and remove the offending application. Be sure to obtain the most recent definition files, since these are critical to the removal of current malware variants.
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