Feb 25, 2011 08:55 GMT  ·  By

A new wave of rogue emails posing as official notifications from Twitter and containing links to illegal online pharmacies have landed in people's inboxes during the last couple of days.

According to Belgian email security vendor MX Lab, who intercepted some of the messages, the emails bear a subject of "Twitter Notification" and purport to come from a @postmaster.twitter.com address.

It appears the spammers modified a legit Twitter email template in order to make their messages look as legitimate as possible.

Recipients are informed they have pending notifications in their Twitter accounts and an URL is provided to see them. However, the link actually leads to a website selling male enhancement pills, pain killers and antibiotics.

The website is part of the "U.S. Drugs" rogue pharmacy chain, one of several affiliate programs that rose to prominence after the fall of "Canadian Pharmacy" last year.

According to Spamtrackers EU, the U.S. Drugs websites are usually hosted on hacked servers and display deceptive elements such as a fake pharmacy license number, fake Verified by Visa logo or fake Verisign and FDA links.

Pharmaceuticals has been the highest ranking spam category throughout last year, even with the October closure of Spamit, the largest rogue online pharmacy affiliate program.

Users are strongly advised against buying from such websites. The drugs sold can be fake or can contain controlled substances in dangerous amounts, posing serious health risks.

In addition, buying from spam carries a very high risk of credit card fraud, because the people behind these operations don't miss out on any chance to make money illegaly.

Users are advised to excercise caution when dealing with links in emails, regardless if they appear to originate from trusted sources. Hoovering the mouse over them should provide an indication of where they actually lead.