Fake Source Codes is a program designed by Jeremy and Aelita. It implants fake source codes into a spectre. This will destroy any spectre that tries to take them from a Warrior. This can easily stop X.A.N.A. from gaining power (or it can drain X.A.N.A. of its power). In How to Fool X.A.N.A., they use Ulrich as a guinea pig. First, the code are implanted into him through a tower. Then they simply wait for a spectre to come. It was intended that a spectre grab Ulrich, absorb the fake source codes, then with a simple keyboard command on the supercomputer, the spectre would be destroyed. Sadly, X.A.N.A. saw it coming and avoided Ulrich and went after Yumi instead. However, just when the spectre was about to grab Yumi and absorb her source codes, Ulrich arrives and grabs the spectre from behind, forcing the spectre to absorb the fake source codes, which eventually destroys it.