It'd make sense if they had a user nuke at there disposal. just delete all posts by such and such user. Not too hard to code if they haven't. Just test it on a dummy version first please. I deleted all my user's and permissions on my last database thanks to a rouge var carrying into the query.
Time for a format then. You have no clue whether your machine is actually secure or not now. Who knows what kind of rootkits/etc. it left behind or if something else brought it here. Whatever you do on your PC until you format it could be compromised. I'd argue it's not even worth removing malware, just nuke it from orbit,…