To reenforce this idea, understand what Par::Packer does: It effectively makes a compressed executable that when run unpacks everything into the system's temp folder and executes your script with the packed in version of perl and all of the dependencies. Finding what's in your script is trivial for anyone remotely familiar with the OS that the pp executable is being run on.

Also, like I said above, it's a compressed executable. Unpacking the pp executable is trivial. 7zip handles it on Win32, and while I'm not entirely clear as to what does it in other places, it wouldn't be hard to figure it out.