A new web-based attack is making the rounds that tries to spread poisonous links by hijacking end users' clipboards.
Forum discussions here, here, here, here and elsewhere all report the same thing: the commenter surfs to a seemingly legitimate site (MSNBC.com comes up more than once) and suddenly a malicious link is copied to the clipboard. The rogue link remains even after the user copies a new batch of text. The only way to remove it is to reboot the computer.
The attack has been reported by Firefox users running both OS X and Windows, but we wouldn't be surprised to hear that other browsers and operating systems are also vulnerable. It's unclear exactly how the attack spreads....
Clipboards hijacked in web attack