Some details of the exploit were posted Wednesday night on the Web site PS2nfo.com, along with lists showing all the files pulled off the game discs for "Ridge Racers," "Wipeout Pure" and "Vampire Chronicles."
The games are not yet playable because there is no way to burn UMDs from scratch, and the PSP does not accommodate larger discs. However, the site said the ability to look through the games' file structures could still be instructive for developers.
A spokesman for Sony Computer Entertainment of America was not immediately available for comment.
Sony released the PSP on March 24 in North America, and the device has sold well since. Movie studios are gearing up to release some of their films on the UMD format, though it was not immediately clear if the techniques used to extract the game files would also work for films.