So basically what i know, is that antiviruses search for some specific signatures in virus. I haven't been able to find these definitions ( it took 4 hours to clear this up for myself ), but basically, the idea is simple.
You just get hex editor, then open your virus with it, and remove certain signatures, that antivirus has in its database.

unfortunately i am too inexperienced in this, and thats why i am unable to find signatures in the internet, that antivirus searches for when scanning a file, though i see many people posting hints on how to do it, but i was unable to gather any important info for doing this.

Anyway, this is probably the best way to make your virus/keylogger undetectable, only if someone knew what to delete with the hexeditor.

So if anyone knows what to delete and how, could be kind enough to enlighten me?

more info ( well the basic idea is explained in here more specifically http://community.vietfun.com/printthread.php?t=279822)

-Nikize