The security firm said that it has spotted a new trojan that steals credit card information by posing as an anti-piracy control for Windows XP.
The phishing trojan mimicks the behavior of Microsoft's Windows Genuine Advantage (WGA) anti-piracy software, which tracks down pirated copies of the operating system.
On startup, the trojan produces a window informing the user that their copy of Windows has been activated by another user. In order to "re-activate" Windows, the software asks the user to input a phone number, e-mail address, and credit card details.
When a user chooses not to enter the data, the trojan automatically shuts down the machine.