I'm astonished that this thread hasn't yet mentioned https://www.ecb.torontomu.ca/~elf/hack/recovery.html https://www.ecb.torontomu.ca/~elf/hack/recovery.html

I'm astonished that this thread hasn't yet mentioned https://www.ecb.torontomu.ca/~elf/hack/recovery.html https://www.ecb.torontomu.ca/~elf/hack/recovery.html Long story short, someone accidentally did rf -rf * in the wrong place as root, and they had to rebuild the system enough to restore from the backups, including writing an executable in machine code as hex and then converting it to binary to call the appropriate system call to effectively "mkdir /etc". It wasn't Linux, but close enough.