Shortened URLs scams spike in June

by Dan Leahul, Brand Republic 08-Jul-09, 11:15

LONDON - URL shortening websites, used by many character-conscious Twitter users, are providing an easy way for spammers to infiltrate computers by masking malware infested websites through blind links.

A new study by online security firm MessageLabs found the amount of URL shortening scams skyrockted in June, after being relatively non-existent in April and May, and now appears in more than 2% of all spam.

Shortened URLs, from sites such as TinyURL.com and Bit.ly, allow scammers to hide actual web addresses from users and are commonly used on social networking websites like Twitter, where message length comes at a 140 character premium.

URL shortening websites are usually free to use and do not require registration, which make it easy for scammers who would otherwise have to work around a distorted word puzzle, or Captcha, to mask the domain name.

Paul Wood, a senior analyst at MessageLabs, said the recent spike in scams of this nature usually indicate that a spammer has found some method of automating the creation of shortened URLs.

A major botnet called Donbot has been fingered as the likely culprit behind the recent influx, said Wood, which has a history of installing malware on user's computers, usually through display advertising.

Wood said: "Donbot, the botnet responsible for sending approximately five billion spam messages every day, is one of the main culprits for using this technique.

"Links of any size all need to be treated with caution."

A number of websites, including Untiny.com, can expand the shortened URLs into the original web address to make sure the link is authentic.