Strange referring url

[final kaoss]

Is this a known exploit of some sorts on unpatched vbulletins or what's up with it??

Ok I was looking through my error log and I noticed this strange entry

[Tue Feb 16 18:09:30 2010] [error] [client 203.199.50.19] File does not exist: /home/vgchat/public_html/:8080&HOST=bjdns2.cncmax.cn&R=,
referer: http://vgchat.info/:8080&HOST=bjdns2.cncmax.cn&R=/forum/register.php&a=act&u=1809&i=cd7b6de577e2f4ade99a217654c6788f8b375dea

[Marco van Herwaarden]

It is not a known vulnerability on standard vBulletin installations, i can you that much. (PS This would have been better asked on vBulletin.com).

It might be (an attempt to) a hack attempt of a modification or such.