You could make a complete ring0 hack and it could get detected by vac.
Hash changed? I assume the MD5 of the exe or something. This would be inconvenient, If TAC/VAC scanned every file on your PC then looked up that hash it would take hours to days.
Again, Inconvenient and hard.
Or you could just manual map in ring0.
Obfuscation only stops people like me and you from reading the code. ain't gonna stop vac.
EDIT: To go vac 'undetected' You would need to emulate the hole VAC system.