This is a generic name for potentially malicious JS scripts that may bypass certain popup blockers in order to show ads and sometimes install malware agents in the form of ActiveX components.
Please let BitDefender disinfect your files.
Marian RADU, virus researcher
Embedded or standalone JS script that by means of popup blocking bypassing routines diplays unwated adware and, in some versions, install malware ActiveX from www.tbcode.com, detected as Trojan.Downloader.Istbar.[version], witch acts as a third party malware downloader.
A cookie is sometimes set for tracking purposes.
For more information regarding the downloaded ActiveX please see the description of Trojan.Downloader.Istbar.OK as an example.