This is most likely an official application signed by Sony.  It doesn't really seem that unlikely either.

Assuming no exploit, it's theoretically and computationally infeasible to "crack" the signing process (this includes any form of "hex editing code", as, obviously, any decent protection scheme has integrity checks).  It is FAR more likely that either:
a) it is an official application (most likely)
b) the private key was leaked/'borrowed' (unlikely, but far more likely than determining the key via other means)