This indicates an attempt to exploit a buffer-overflow vulnerability in OScan8.ocx and Oscan81.ocx, which are included by default in BitDefender's Online Anti-Virus Scanner.
The vulnerability is caused by an error that occurs when the vulnerable software handles a malicious "InitX" property. It allows a remote attacker to execute arbitrary code via a crafted web page.
BitDefender Online Anti-Virus Scanner 8.0 released on or prior to May 24th 2006.
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the patch available from the web site: