You'd think that if you were going to commit a crime, impersonating a major law enforcement agency would be the last attack on your list. But some brassy phishers have got another idea.

According to a warning issued earlier today by Websense Security Labs, there is a new spam attack on the Web that claims to be a message from the U.S. Department of Justice.

The message claims that a complaint against the recipient's company has been filed to the DOJ. The email informs the reader that a copy of the original complaint has been attached to the email. The attached "complaint" is a Trojan Downloader .scr file.

None of the currently available antivirus programs can detect the Trojan, Websense says.

Interestingly, the .scr "screen saver" format is also being used in a different attack being reported today, this one under the guise of the Better Business Bureau.

According to researchers at MessageLabs, the messages purport to be from the BBB and mention employees' specific names and organizations in the subject lines to cover their true intent, which is to deliver malware.

The two attacks are a shift back to malicious attachments, following a trend toward embedded links to phishing sites, MessageLabs observes.

— Tim Wilson, Site Editor, Dark Reading