TL;DR: Python audit hook "sandbox". Use \_\_builtins\_\_, the garbage collector, and the global namespace of \_\_main\_\_ do deactivate the \_\_exit call in the audit hook.

[Link to write-up](https://github.com/fab1ano/hxp-ctf-20/tree/master/audited)

Original writeup (https://github.com/fab1ano/hxp-ctf-20/tree/master/audited).