One recent attack, which aims to swipe users' banking information, is capitalizing on the release of the first official Twitter iPhone application. Click a link in an attacker's Twitter post -- one offending message says it's the "Official Twitter App" -- and get directed to a website hosting a Trojan application. Run it, and your Windows PC can end up compromised by a worm that's gunning for your online banking credentials.
According to Dmitry Bestuzhev, a security expert at Kaspersky Lab, the Trojan -- which it dubs "Worm.Win32.VBNA.b" -- can also replicate via USB devices, disable the task manager in Windows, and suppress Windows Security Center alerts.
This attack differs from another popular way to attack Twitter users -- namely, through Rogue AV malware. Briefly, Rogue AV uses a link in a Twitter post to direct a user to a website with a fake video. Click on it, and the website offers to let you download an application, which is actually malware.
While Twitter may be a boon for microbloggers, as the above attacks demonstrate, the site is also favored by attackers, who find its features useful. For example, by using URL-shortening services such as Bit.ly, "they can easily track the geographical location of their victims and general infection statistics -- by numbers of clicks -- after they post the link," said Bestuzhev.
In other words, attackers have a Web-based mechanism for not only launching attacks, but checking their efficacy, simply by searching for the shortened URLs they use to attack Twitter users to sites harboring malware.
Should Twitter be doing more to stop these prevalent attacks?
"The Twitter security team is trying to do its best," said Bestuzhev. "Once a malicious URL is detected, it gets reported to be blocked. Unfortunately, in some cases, it can't be done quickly enough, since third parties are also involved: short-URL services, hosting and domain providers. The criminals know this so, they have at least minutes, to some hours of 'alive time,' to infect people by using the same malicious URL."
Then, once the URL is compromised, they can review the list of hot topics, and target a new one. "It never ends," he said. "Every week there are new attacks going through Twitter but using different trending topics and a bit different technique."