The US Federal Trade Commission has become the latest government agency to be used as a front for email attacks. 

Email security provider MX Logic said that it had found multiple instances of fraudulent emails claiming to be from the organisation. 

The messages notify users that they have filed a complaint with the agency and include a document with a copy of the alleged complaint.

Users who open the document become infected with a key-logger that can be used to steal log-in information and other confidential data.

Sam Masiello, director of the MX Logic Threat Center, believes that the attack is related to two prior spam runs in which the senders posed as government agencies. 

A scam in January used bogus tax refund claims to lure victims, while emails appearing to be from the Better Business Bureau were sent in May to install key-loggers on victims' PCs. 

"I would guess that these different variants are being sent by the same spam gang, and are targeting the same people with each new run," Masiello said in an posting on a company blog. 

The attacks have similar patterns in that they target business executives and managers, are highly personalised and use a malicious RTF file to install the key-loggers.

Masiello urged users to delete the email if an attack attempt is suspected.