This indicates an attack attempt against a buffer-overflow vulnerability in Symantec SupportSoft ActiveX control.
The vulnerability is caused by the failure to properly check user-supplied input before using it. It may allow a remote attacker to execute arbitrary code by enticing users into visiting a specially crafted web page.
SupportSoft ActiveX Controls versions 5.x
SupportSoft ActiveX Controls versions 6.x
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patch, available from the web site: