Have you ever heard about the famous "green screen"? No, it's not a screensaver... Believe me, it still does exist! In many industries, although the front-end systems are all new and shiny, in the back-end they still rely on well-known, proven IBM i (aka AS/400) technology for their back-office, core systems. Surprisingly, nobody truly seems to care about the security. Even if these nice IBM heavy black boxes are directly connected to the Internet... The aim of the talk is to give you more insight in a number of techniques for performing a security test of / securing an IBM i system from perspective of an external and internal intruder. Methods like privilege escalation by nested user switching, getting full system access via JDBC or bypassing the "green screen" (5250) limitations will be presented. Last but not least: I will also show a undocumented output format of the built-in password transfer API, giving you direct access to all password hashes. Even IBM engineers may wonder...