$ cat writeup.md…
$ cat writeup.md…
spbctf
Task: ELF64 'malware' that reboots the host (reboot syscall gated on getuid) unless run as root, hiding an RC4-style decryptor. Solution: statically reverse the cipher, recognize the magic-number division reveals modulus 129 (not 256) over a 129-entry S-box, and reimplement the modified RC4 in Python to decrypt the flag offline.
Permission denied (requires tier.pro)
Sign in with GitHub, Discord, or Google to continue. No email required.
$sign in$ grep --similar