Jul 29, 2011 11:26 GMT  ·  By

Security researchers warn that thousands of Twitter accounts have been hijacked during the past several days and are being used to push weight loss spam.

The spam messages read: "Get the beach body you've always wanted, now you can with this weight loss supplement http://channel3online.com"

The link takes users to a rogue page that mimics the appearance of a news TV channel's website. The names of important women's magazines are also used on the page to add credibility.

The site displays a story entitled "Acai Berry Diet Exposed: Miracle Diet!" which encourages users to buy supplements. The scammers even mention their own success in distributing this kind of spam.

"Acai berries are the latest weight loss fad. [...] Like you have probably already seen, they are all over the Internet in blogs with success stories of people who have apparently used the pills and lost a ton of weight," they write in the fake article.

Indeed, the acai berry spam has been going on for years now and has spread virtually everywhere. Mimicking news websites is a popular technique used by the people behind these campaigns.

Back in April, the FTC shut down ten spam operations centered around acai berry. "Almost everything about these sites is fake. The weight loss results, the so-called investigations, the reporters, the consumer testimonials, and the attempt to portray an objective, journalistic endeavor," warned David Vladeck, director of the FTC’s Bureau of Consumer Protection, at the time.

The method used to hijack the Twitter accounts is not yet known. Graham Cluley, a senior technology consultant at Sophos, thinks that some of the recent leaks of email addresses and passwords might have something to do with it.

"If your account on Twitter has been compromised, make sure you change your password to a non-dictionary word - and be sure to also change any other online accounts where you might be using the same password. Far too many people use the same passwords on multiple sites, which obviously increases your chances of becoming hacked," he warns.