The latest anti virus review from the Symantec MessageLabs Intelligence unit, produced by the company which develops the Norton Antivirus software, warns that spammers are making greater use of shortened hyperlinks.

The anti virus review shows that over the last 12 months, the percentage of spam which contains shortened hyperlinks has dramatically increased from a one-day peak of 18% on 30 April, 2010, compared to just short of 10% in 2009.

And 18% equates to just over 23 billion emails. Another way to see it is that for some days in 2010, around 5% of all spam messages contained shortened hyperlinks.

Paul Wood, MessageLabs Intelligence Senior Analyst, at Symantec Hosted Services, the team behind Norton Antivirus, said:
“As far as spammers are concerned, any tactics that make it harder to block their spam emails are going to be exploited. When spammers include a shortened URL in spam messages, these shortened hyperlinks contain reputable and legitimate domains, making it harder for traditional anti-spam filters to identify the messages as spam based on the reputation of the domains found in the spam emails.
“While botnets are often the source of short URL spam, 28% of this type of spam originated from sources not linked to a known botnet such as unidentified spam-sending botnets or non-botnet sources such as webmail accounts created using CAPTCHA-breaking tools.”

The anti virus review also stated that spammers shortened hyperlink strategy is working. For every 74,000 spam emails which contained a shortened url link, one website visit was generated. Furthermore, the most often used shortened hyperlink contained within spam got more than 63,000 website visits.

The various Norton Antivirus Software packages are continually updated from information supplied by the Symantec MessageLabs Intelligence unit.

Guest Article by Neil Camp