63 words
1 minutes
SCSC2026 Quals - ngemal - Reverse Engineering Writeup

Category: Reverse Engineering
File: flag.txt.wowok
Flag: SCSC26{sesudah_kesulitan_itu_kemudahan}

Challenge Description#

A file named flag.txt.wowok was provided. Its contents looked random/garbled.

Analysis#

Since the flag format is known (SCSC26{...}), the simplest approach is brute-forcing a 1-byte XOR key (0–255) and checking for the substring SCSC26{ in the decoded output.

Exploitation#

Bruteforce found the key 0x32 (50). XOR-ing the file with that key reveals the plaintext flag.

Example 1-liner (Python):

d=open("flag.txt.wowok","rb").read()
print(bytes(b^0x32 for b in d).decode())
SCSC2026 Quals - ngemal - Reverse Engineering Writeup
https://blog.rei.my.id/posts/10/scsc2026-quals-ngemal-reverse-engineering-writeup/
Author
Reidho Satria
Published at
2026-02-17
License
CC BY-NC-SA 4.0