I have encountered the killvbs.vbs problem
have you done the 8-steps? what anti-virus programme are you using? in my opinion, there are some processes in your hjt log. but best if you do the 8-steps first and then post your logs up. Yes, it's a long process but it's for the best.
oh wait.. i just noticed it's on your flashdrive... er... reformat the flashdrive? well you can do the 8 steps as well i think.
Hi here are my logs from the following