What is a "Downloader.tibs" Virus

Hello computer genius'!
I just got a detection off AVG telling me that it has found a Downloader.tibs virus in syst.exe. I was just wondering how dangerous it was and what it could possibly do to my computer should I allow it to live? I would also wondering where it came from, I doubt it is new as it was instantly detected after I updated the virus database.
All information appreciated,
Avlvs

According to McAffee's virus definitions:

"This is a trojan downloader that connects to a remote website and downloads trojan component on the user's system." Threat to system is rated as low. Updating your Java to version 5 update 6 or later will utterly disable the beastie. Linky.

Thanks.