Symantec says it has identified a phishing scam that attempts to fool the victim by faking a Microsoft Windows piracy-control warning and demanding a credit card.

According to Symantec, the phishing scam, which is activated by a piece of Trojan software called Trojan.kardphisher, starts the process by presenting a highly accurate-looking Microsoft Windows piracy-control warning when the victim’s personal computer is turned on.

The warning falsely tells the user that there’s a software-licensing violation and asks them to choose either “yes” or ‘no” to “activate” the Windows software. The victim can choose only “yes” or “no” and can’t run Task Manager or any other application, according to Symantec. “If you choose 'no,' your PC will be shut down immediately,” Symantec states in its Security response Weblog entry describing the attack.

If the victim clicks on “yes,” the phishing scam proceeds to ask the user to enter billing information and a credit card, which would then presumably be used fraudulently.

Symantec emphasized that the Trojan in question teaches the lesson “Trust No One,” because such Trojans can be used to effectively impersonate Microsoft, banks or government organizations. “It’s far better to doubt a genuine request until proper verification is provided than it is to blindly place your trust in a communiqué simply because it appears to have come from a trusted source,” the Symantec security earning states.