Viruses/Worms News

Twitter blocking links to known malware sites

Tuesday, August 4, 2009

In response to a recent rise in spam, malware and worms threatening the online security of its users, micro-blogging site Twitter has begun blocking links to known malware sites.

Web security firm F-Secure first reported the malware link blocking on its blog yesterday. After attempting to post a link to a website that hosts malware, a message appears that says: "Oops! Your tweet contained a URL to a known malware site!"

Security experts have been warning for some time that the use of URL shortening on the site presents a security risk, because the shortened URLs don't reveal what domain or website a user will be sent to upon clicking.

Last month, hackers managed to hijack some 2.2 million links posted through the URL shortening service Cligs, redirecting the links to a non-malicious page on freedomblogging.com, a website of the OC Register.

Trend Micro reported that hackers have used TinyURL - the largest of the URL shortening services - to direct users via instant messages on Facebook, Google Chat and AOL Instant Messenger to a phishing website.

Spammers have increasingly used shortened URLs in spam email and instant messages.