The RCMP is warning Canadians about a new computer virus that claims to come from law enforcement agencies and warns users they've been linked with child porn.

The malware causes computers to freeze after a pop-up message appears saying the computer has been associated with illegal music downloading or child pornography, and asks for a payment of $100 to "unlock" it.

The message claims to come from the RCMP, CSIS or the FBI. "These types of messages, known as ransomware, are scams designed to create shock and anxiety so that victims respond by sending money quickly," the RCMP said.

Cops say neither they nor the government would "hijack" a computer this way or ask suspected criminals to pay a fee to have their computers restored. They warn Canadians not to send money - it won't unlock the computer or remove the malware. Users who don't know how to find and get rid of malicious software should get the help a professional computer tech.