On the system I'm currently on:

$ file $(which rename)
/usr/bin/rename: ELF 32-bit LSB executable, Intel 80386, version 1 (SY
+SV), for GNU/Linux 2.0.0, dynamically linked (uses shared libs), stri
+pped
[download]

However from the description you give of perl's rename it seems it lets you run arbitrary code. I hope it uses Safe; although I heard some experienced and knowledgeable perl hacker say that even that isn't really bulletproof...