"Joanna Rutkowska has always been a big supporter of the Windows Vista security model. Until she stumbled upon a "very severe hole" in the design of UAC (User Account Control) and found out — from Microsoft officials — that the default no-admin setting isn't even a security mechanism anymore.
Rutkowska, a hacker with a track record of defeating Vista's security mechanisms, believes UAC has a major flaw in the way it automatically assumes that all setup programs (application installers) should be run with administrator privileges.
"[When] you try to run such a program, you get a UAC prompt and you have only two choices: either to agree to run this application as administrator or to disallow running it at all. That means that if you downloaded some freeware Tetris game, you will have to run its installer as administrator, giving it not only full access to all your file system and registry, but also allowing it to load kernel drivers! Why should a Tetris installer be allowed to load kernel drivers?," Rutkowska asked in a post on her Invisible Things blog."
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