You asked what your son has done now.
He's visiting certain sites - usually porn or hacker portal sites - and clicking on image links that install an .exe programme. The executable programme then provides access to the desired files. You may find that there is a deletion programme installed on your PC by means of which teenagers can clear their tracks when they log-off.
Never let teenagers near your own PC. They've b*ggered mine up something wicked. As to .vbs files - never open them. The consequences are dire, although you will become an expert in reconstructing your files and folders. You may even learn the secrets of The Cult of the Dead Cow. But believe me, you really have better ways to spend your time. If the worst happens, trash the PC and buy a new one. Then keep it locked up when you aren't using it. With an old fashioned locked cupboard solution I mean.
ZDNet is a useful source of programmes for tracking down and fixing bugs. Be careful though. Freeware is often loaded. Isn't cyber-life fun? Like visiting Patpong, you never know what you're getting until you've got it!
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Through difficulties to the cinema