Résolution faite sous Linux, l’utilitaire gdisk est donc nécessaire :
$ sudo apt install gdisk -y
Pour traiter le fichier .Zp, j’ai utilisé p7zip :
$ sudo apt install p7zip-full
Le .7z cachait en réalité un .raw :
$ 7za x fcsc.7z
7-Zip (a) 24.08 (x64) : Copyright (c) 1999-2024 Igor Pavlov : 2024-08-11
64-bit locale=en_US.UTF-8 Threads:12 OPEN_MAX:1024
Scanning the drive for archives:
1 file, 5360255995 bytes (5112 MiB)
Extracting archive: fcsc.7z
--
Path = fcsc.7z
Type = 7z
Physical Size = 5360255995
Headers Size = 122
Method = LZMA2:24
Solid = -
Blocks = 1
Everything is Ok
Size: 10737418240
Compressed: 5360255995
$ ls
fcsc2.7z fcsc.7z fcsc.raw
La commande file nous indique qu’il s’agit ici d’une table de partition :
$ file fcsc.raw
fcsc.raw: DOS/MBR boot sector, extended partition table (last)
Il suffit d’utiliser l’utilitaire gdisk installait au début avec l’option -l pour récupérer notre flag :
$ file fcsc.raw
$ gdisk -l fcsc.raw
GPT fdisk (gdisk) version 1.0.10
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Disk fcsc.raw: 20971520 sectors, 10.0 GiB
Sector size (logical): 512 bytes
Disk identifier (GUID): 60DA4A85-6F6F-4043-8A38-0AB83853E6DC
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 20971486
Partitions will be aligned on 2048-sector boundaries
Total free space is 4029 sectors (2.0 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 4095 1024.0 KiB EF02
2 4096 1861631 907.0 MiB 8300
3 1861632 20969471 9.1 GiB 8300
Le flag est FCSC{60DA4A85-6F6F-4043-8A38-0AB83853E6DC}.