Possibly high network activity.
Please let BitDefender disinfect your files.
Daniel RADU, virus researcher
Trojan.Downloader.Vb.OC is a component of another malware , Winks Installer which disguises itself as a a patch for MSN Messenger to add new emoticons.
It downloads updates from these links:
At the time of the analysis the download site is not online anymore.
Newly downloaded updates are handled by Winks Installer.