Beware of short URLs
Spammers seem to have found a new way to sell their questionable products. Most e-mails which link to cheap university diploma's or little blue pills which keep you going all night are blocked by current spam filters. Behold the power of short URLs. Companies like Bit.ly and TinyURL offer link shortening services. An unfortunate side-effect of these services is the fact that the true destination of the link is obscured. A feature that caught the eye of spammers.
URL shortening techniques have been around for years. A company like TinyURL was founded in 2002. In the early years URL shortening was used to correctly display long links in e-mails which would normally be split due to the limited line length of 80 characters. The rise of Twitter caused a new boost for URL shortening services. In order to stay within the maximum of 140 characters, short URLs are a must. Twitter even automatically converts URLs of more than 26 characters.
Disadvantage
The advantage of this space saver is also a disadvantage. Encrypted links completely obscure the true destination. Before clicking you have no idea which page you're surfing to. So beware of evil websites which may bombard you with phishing attacks or viruses.
It seems that not only Twitter users discovered the benefits of short, and therefore obscured links. Spam results from MessageLabs show a significant increase of short URL usage in spam messages over the last few weeks. Spam filters fail to detect these coded links to websites offering blue pleasure pills and cheap diploma's, which increases the chance of these messages entering you inbox.
A dramatic increase in short URL usage in spam (Credits: MessageLabs)
How to handle this
It's hard to prevent concealed spam messages with shortened URLs to flood our mailboxes. We have to wait for spam filters to actively block messages with shortened URLs from services like Bit.ly and TinyURL. They could possibly check short URLs for their true destination. In the meantime it's a matter of not clicking on short URLs in obscure e-mails.
This also means that it's better not to use short URLs in your own e-mails. First of all it doesn't look professional, we don't really need to save space and when the service stops working all our links will be dead. And think about the moment spam filters start blocking short URLs? Your legitimate e-mail could get marked as spam and you will be blacklisted.
To protect yourself online, when using Twitter for instance, you can use browser add-ons like Long URL Please or Bit.ly's Preview Plugin, both for Mozilla Firefox. These add-ons convert short URLs to the original links, which allows you to see you surfing destination before clicking. Quite a nice thought, if you can still have some influence these days...
