Rating:

Binary with totally altered program flow (everything done trough signals etc).
Steps to solve (very brief, more in writeup):
- Find function that prints info about bad password
- Find function that sets info about bad password
- Open up gdb, and break on this function to read password char by char.

Original writeup (https://wiki.armiaprezesa.pl/books/wpictf2019/page/run_s0m3_w4r3z).