Microsoft has warned Web surfers that an unused ActiveX control in Internet Explorer could let hackers launch malicious code on the user's system if it's running an older OS like Windows XP or Windows Server 2003. Hackers have reportedly already begun exploiting the vulnerability, and security experts predict the attacks could get worse. Microsoft has posted a fix for the problem online.

Microsoft has warned Web surfers that an unused ActiveX control in Internet Explorer could let hackers launch malicious code on the user's system if it's running an older OS like Windows XP or Windows Server 2003. Hackers have reportedly already begun exploiting the vulnerability, and security experts predict the attacks could get worse. Microsoft has posted a fix for the problem online. The flaw, which resides in Microsoft Video ActiveX Control, connects Microsoft DirectShow filters for use in capturing, recording and playing video.