The Khatrimaza-org-mkv -

$ python3 xor.py hidden.bin s3cr3t_k3y_4_f1ag payload.bin 🎉

# 2. List attachments (if any) $ mkvextract attachments khatrimaza-org.mkv : The Khatrimaza-org-mkv

$ hexdump -C hidden.bin | head 00000000 42 49 4e 41 52 59 20 66 69 6c 65 20 73 69 67 6e |BINARY file sign| 00000010 61 74 75 72 65 20 70 72 6f 74 65 63 74 65 64 20 |ature protected | ... The first bytes read – looks like a custom marker added by the challenge creator. 5.2 Entropy check – is it compressed / encrypted? $ ent hidden.bin Entropy = 7.998997 bits per byte. Very high entropy (~8 bits/byte) – it is either compressed or encrypted. 5.3 Try common decompression tools We test a few common formats with binwalk : $ python3 xor