It takes real audacity to impersonate the folks who'll prosecute you if they catch you in an illegal act. Yet that's exactly what a scam artist did by sending out fraudulent spam messages claiming to be from the U.S. Department of Justice (DOJ).

The messages, addressed "Dear Citizen," assert that the recipients, or their businesses, are the subject of complaints filed with the DOJ and the Internal Revenue Service, according to a DOJ advisory. In addition, the emails provide case numbers and state that the complaint was "filed [sic] by Mr. Henry Stewart."

The DOJ also revealed that its logo may appear at the top of the email message or in an attached file, and that the message may include a supposed copy of the complaint and contact information for Stewart.

"Criminals are increasingly using U.S. government brands to trick consumers into phishing and malware scams," said Avivah Litan, a Gartner analyst. "It just validates their disdain, contempt and scorn for Americans. If you check out the criminal chat rooms and message boards, you will note a general theme of making Americans out to be totally naïve idiots while beating (scammers') own chests for being able to out-manipulate and scam the U.S. population."

The DOJ warned that recipients should be wary of unsolicited warning messages that purport to come from government agencies. Several other government entities - the FBI, the Federal Trade Commission and the IRS - have been the source of similar hoaxes, it said.

Double-clicking on attachments could place malicious software, such as a virus or keystroke logger, on recipients' PCs, according to the Justice Department.

"These criminals are motivated not only by financial gain but also by a perverse political and fanatic psychology, which makes them all the more dangerous," said Litan.

The Department of Justice offers websites with information on spyware at http://onguardonline.gov/spyware.html and phishing http://onguardonline.gov/phishing.html.