Several researchers discovered that Microsoft was actually updating nine files in Windows Vista and Windows XP SP2 without the users consent and with automatic updates turned off. The nine files in question are not the same and they seem to the update mechanism itself.

It still raises the question if Microsoft should be allowed to update files on your system without asking for your permission instead. While the updates this time did not seem to be critical or change functionality it could very well be that Microsoft decides to do so the next time. I’m thinking of DRM and anti-piracy measures for instance.

The changed files in Windows Vista are:

• wuapi.dll
• wuapp.exe
• wuauclt.exe
• wuaueng.dll
• wucltux.dll
• wudriver.dll
• wups.dll
• wups2.dll
• wuwebv.dll

The ones in Windows XP are:

• cdm.dll
• wuapi.dll
• wuauclt.exe
• wuaucpl.cpl
• wuaueng.dll
• wucltui.dll
• wups.dll
• wups2.dll
• wuweb.dll

Computerworld article
Zdnet blog entry