Need help on .hack//outbreak

Does anyone know were to get virus core H?My mom and I think that you have to data drain these horse things(It looks like a horse that has his back-end missing and has somone on his back) to get it.Can somone give me the keywords that has those monsters,or better yet,A place were your pretty sure the virus core is at.I need atleast one of those virus cores to be able to gate hack.

Head over to Sigma Server: Entwined Prejudiced Chaos. Fight Nightmare. Drops Virus Core H. It's a lvl 65 monster.

Thanks,I'll try that.BTW,if anyone needs help on .hack//OUTBREAK,you can post what you need help on here and get help on it.Thanks again:)