Warning From Microsoft on False Digital Signatures
The Microsoft Corporation warned computer users today that someone posing electronically as a company executive had fooled VeriSign Inc, a provider of digital signatures, into issuing fraudulent electronic certificates in Microsoft's name.

The false documents could potentially be used by software virus writers or other vandals trying to trick unsuspecting users into running hostile programs on their computers.
http://www.nytimes.com/2001/03/23/technology/23SOFT.html?pagewanted=all