As well as misusing Event Viewer, ASSOC or a system CLSID, scammers hijack “prefetch” and “inf” to con victims into believing they have malware.

…the scammer doesn’t need you to edit the registry to find the CLSID he’s looking for. He simply has to persuade you to run the ASSOC command…

Here's a diagnostic window that your shouldn't panic over, certainly if some cold-calling scammer directs you to it by persuading you to run a diagnostic on your own system. But I'm getting ahead of myself. You might think I've blogged more than enough about support scams already – you know, where someone calls you out