Kaspersky, an anti-virus and computer-security firm based in Moscow, created a tool called Krab Krawler, which extracts URLs from millions of tweets a day. The tools expands shortened URLs to examine words in the web address for those matching known malware sites. For unknown sites, Kaspersky visits the web page to determine if it’s hosting malicious code that could infect visitors.
About 26 percent of Twitter messages contain a URL, according to Costin Raiu, chief security expert at Kaspersky. About half of those appear to be generated by spammers or by people with malicious intent, he said. These URLs get spread quickly in re-tweets.
As many as one in every 500 web addresses posted on Twitter lead to sites hosting malware, according to researchers at Kaspersky Labs who have deployed a tool that examines URLs circulating in tweets.
The spread of malware is aided by the popular use of shortened URLs on Twitter, which generally hide the real website address from users before they click on a link, preventing them from self-filtering links that appear to be dodgy.
