This attack could pose a serious security threat. You should take immediate action to stop any damage or prevent further damage from happening.
This signature detects attempt to trigger a denial of service vulnerability by instantiating WebEx GPCContainer ActiveX Control in Internet Explorer.
WebEx is a sharing and conferencing application for Microsoft Windows.
WebEx is prone to multiple denial-of-service vulnerabilities that stem from a memory-access violation in the 'GpcContainer' ActiveX control. Specifically, a memory-access violation occurs when the AcitveX control is instantiated.
Attackers can exploit these issues to crash applications that use the ActiveX control, denying service to legitimate users.