"If you use the recent ActiveState PerlApp tools, it is possible, but not very easy to decode what the application .exe is doing. If you are up to it and want to take on a challenge, /msg me and I'll send you an .exe for you to de-compile. I think this is difficult."
Agreed. The FAQ states it's possible, and advises against relying on perlapp for hiding sensitive data. I'm sure if one where to google seach this topic they'd find, if not a complete solution, a script to start the on the right track to "de-compile" the generated exe.