THOUSANDS of Twitter users have fallen victim to an ‘exploit’ bug today.

According to reports, Twitter’s web interface is vulnerable to a type of exploit which allows an account to be hijacked and messages sent from a user.

Those affected report hovering over a malicious tweet - one distributor is test_nau - and the message is automatically retweeted to their followers.

The exploit can also be used to force pop-ups to appear on a users’ screen and from there redirect people to third party sites.

Sarah Brown, wife of former Prime Minister Gordon Brown, is one of the more high-profile victims. A link to a Japanese porn site was sent to her one million-plus followers.

Twitter users logging on through phones and other means seem to be unaffected.

People are advised not to use Twitter.com until the problem is resolved.

- Have you been affected? Let us know how by posting a comment below.