Code samples to perform process hollowing on Linux. Full article here: https://www.bencteux.fr/posts/linux_process_hollowing/
Compile:
$ gcc -c hollowing_ptrace hollowing_ptrace.c
Run:
$ ./hollowing_ptrace /usr/lib/firefox-esr/firefox-esr
Check:
ps aux | grep firefox
cat /proc/<pid>/cmdline
pidof firefox-esr