The man from Redruth, Cornwall was nabbed after a company that sells anatomical software bought a copy of its own software on the auction site.
Working with the Federation Against Software Theft, software house Primal Pictures contacted the counterfeiter.
The anti-piracy partners say the man has now promised to cease trading in illegal software and has supplied a written admission of his guilt. He will now negotiate compensation with Primal.
Peter Allan, CEO of Primal Pictures said, "Our software is the product of years of dedicated hard work by anatomists and computer graphic experts, and it is used to train medical and surgical students all over the world.
"We went to Fast to help us settle this without going to court, and we are happy that the rogue seller has ceased his illegal activities so that we can stay in business."