The keygen is NOT infected with any cirus or whatsoever.
But as it is part of a "hacking" tool, certain anti-virus detects it as a potential threat and therefore you are informed that it contains a virus.
I know what I'm talking about, but you gotta trust me, it is not a virus.
I use the latest version of Kaspersky anti-virus and it did not detect any virus from the keygen.
So simply disable your anti-virus temporarily and use the keygen