If you unexpectedly receive a Valentine's Day e-card, be careful, it may not be from a secret admirer, but instead may contain the 'Storm Worm' virus which could infect your computer system.

This warning was issued by the Federal Bureau of Investigation, which said that with the holiday approaching, be on the lookout for spam e-mails spreading the Storm Worm malicious software (malware).

The e-mail directs the recipient to click on a link to retrieve the electronic greeting card (e-card). Once the user clicks on the link, malware is downloaded to the Internet-connected device and causes it to become infected and part of the Storm Worm botnet, the agency said in a press release.

A botnet is a network of compromised machines under the control of a single user. Botnets are typically set up to facilitate criminal activity such as spam e-mail, identity theft, denial of service attacks, and spreading malware to other machines on the Internet.

The Storm Worm virus has capitalised on various holidays in the last year by sending millions of e-mails advertising an e-card link within the text of the spam e-mail. Valentine's Day has been identified as the next target.

Be wary of any e-mail received from an unknown sender. Do not open any unsolicited e-mail and do not click on any links provided, the FBI warned.

Malware Storm Valentines day