The latest manifestation of the Bagle worm has gone back to basics in its attempts to infect computers.

Bagle X entices users to open attachments by claiiming they contain free software, movie clips or pornography.

The worm also copies the domain name in the recipients address, making it appear to come from someone in the same company or at least the same ISP.

Anti-virus company Trend Micro warned that Bagle X any one of the following names: Annie, Christina, Jessie, or SecretGurl, plus the recipient's domain name.

For example, a copy of Bagle X sent to Computeractive might appear to have come from SecretGurl@computeractive.co.uk.

The message uses one of several subject headers, including "Let's socialize, my friend!" or "I'm bored with this life".

Users have been warned to make sure their anti-virus software is up to date and not to open suspect attachments.