Researchers sound alarm about bug in free antivirus scannerDecember 22, 2008 – 6:32 PM
A bug in Trend Micro’s free online virus scanning service can be used by hackers to hijack Windows PCs running Internet Explorer, security researchers warned.
Attackers able to dupe users into visiting a malicious Web page could exploit a vulnerability in the custom ActiveX control that Trend Micro distributes to users of its free HouseCall service, said Danish bug tracker Secunia ASP in an alert posted Sunday.
HouseCall bills itself as a free scanning tool that checks “whether your computer has been infected by viruses, spyware, or other malware.”
“The vulnerability is caused due to a use-after-free error in the HouseCall ActiveX control (Housecall_ActiveX.dll),” said Secunia’s warning. “This can be exploited to dereference previously freed memory by tricking the user into opening a Web page containing a specially crafted ‘notifyOnLoadNative’ callback function.”
Trend Micro has fixed the flaw in the ActiveX control and patched the public HouseCall servers, but it noted that the latter has not been extensively tested, and essentially waived responsibility if it turns out not to be sufficient.