A recent string of high-profile ActiveX vulnerabilities caused the U.S. Computer Emergency Readiness Team (US-CERT) to advise users to disable the ubiquitous Microsoft browser plug-in technology altogether. The vectors for these recent exploits include a third-party image uploading tool used on both the Facebook and MySpace social networking sites, and flaws found in Yahoo's Music Jukebox, Real Networks' RealPlayer, and Apple's QuickTime.
"We're seeing an increase in exploits aimed at these types of tools that are commonly used with a variety of technologies including social networking sites and multimedia players. As online crime becomes more prominent, malicious actors are taking advantage of these types of vulnerabilities to accomplish their objectives," said a spokesman at the U.S. Department of Homeland Security, which oversees the US-CERT.
Security experts contend that there's no end in sight for attacks on the plug-in architecture.
One reason is that there are plenty of security holes in ActiveX to be exploited. But another reason is not Microsoft's fault, they say: any technology used so widely will attract hacker attacks. "There's simply a lot of software out there using ActiveX that's either preloaded or embedded that users don't even realize is there, and that's why it was necessary to make the advisory," the US-CERT spokesman said.
Although features added in Microsoft's newest Web browser, Internet Explorer 7, may help reduce the problem down the road and push attackers to move on to new targets, ActiveX will remain among the leading programs assaulted by opportunistic cyber-criminals, at least for the foreseeable future, several researchers say. After all, they say, Internet Explorer's status as the most used Web browser makes it an attractive target, just as the Windows operating system has been subject to constant attack for the past decade due to its huge market share. "When hackers spend time trying to find vulnerabilities to exploit, they want to make sure that they can affect the highest number of people," said Will Dormann, a vulnerability analyst at the Carnegie Mellon Software Engineering Institute CERT.
A juicy target that's easier to exploit
When you ask researchers which ActiveX exploits make them curl their toes in reaction, the answers don't tend to focus on specific sets of attacks but instead on the sheer volume and variety of the threats, and the vulnerabilities that allow for them.
Some of the most prominent examples of ActiveX exploits include malware attacks aimed at Microsoft's Data Access Component (MDAC) software, which was pummeled for years by a broad range of attacks, and problems with the HTML Help ActiveX control module in Internet Explorer that opened it to numerous types of attacks, most notably the Phel Trojan virus.