Challenge list
CryptographyLevel 4★★★★☆Cryptanalysis - Recovering an LCG's Hidden Parameters
A service generated both session tokens and an encryption keystream from a linear congruential generator x_{k+1} =…
Digital ForensicsLevel 4★★★★☆Recover Damaged RAID5 Array
The RAID5 array `/dev/md0` (4 members) on the file server fs01 no longer assembles after the member sdd failed.…
Digital ForensicsLevel 4★★★★☆Reconstruct Attack Scenario from Multiple Logs
`/challenge/web.log`, `/challenge/auth.log` and `/challenge/db.log` record the same intrusion among a lot of…
Digital ForensicsLevel 5★★★★★Reconstruct Full APT Attack Stages
Four logs, `/challenge/edr_process.log`, `proxy_http.log`, `dns_queries.log` and `dlp_transfer.log`, hold an APT…
Digital ForensicsLevel 5★★★★★Crack BitLocker Encrypted Drive
Learn BitLocker recovery-key verification with a safe metadata fixture. bitlocker.img is not a real volume. Identify…
Digital ForensicsLevel 5★★★★★Extract Message Hidden in Bitcoin Transaction
The victim paid the ransom to the Bitcoin address `bc1qr4nsmw4r3pay7hzfx0d9cq3vkt8e6m5ljgs2ua`.…
Digital ForensicsLevel 5★★★★★Extract Secret Key from IoT Device Firmware
Analyze the update file `/home/ctfuser/evidence/firmware.bin` of the network camera KNC-CAM-2000 (do not connect to a…
Network SecurityLevel 5★★★★★Network Analysis - IPv4 Overlapping Fragment Reassembly
The UDP datagram with IPv4 ID 0xbeef in fragments.pcap contains overlapping fragments that overwrite earlier bytes.…
Digital ForensicsLevel 5★★★★★Extract VM Information from Hypervisor Memory
Analyze the KVM host memory dump `/home/ctfuser/evidence/kvm_host.dump`. The guests are configured like AMD SEV, so…
Digital ForensicsLevel 5★★★★★Detect Process Hollowing Attack
From the memory of a Windows host, the process list `process_list.txt` (the PEB view), the VAD list `vad_regions.txt`…
Digital ForensicsLevel 5★★★★★Detect Tampered Timestamps
`/challenge/mft_timeline.csv` is a timeline exported from the NTFS `$MFT`. It has the `$STANDARD_INFORMATION` (SI) and…
Digital ForensicsLevel 5★★★★★Decrypt Encrypted iOS Backup
Verify the password of an encrypted iOS backup with a safe iTunes metadata fixture. No real iPhone or backup is used.…
CryptographyLevel 5★★★★★Cryptanalysis - RSA e=3 Broadcast Attack
broadcast.json contains the same plaintext encrypted with unpadded RSA e=3 under three pairwise-coprime moduli.…
Digital ForensicsLevel 5★★★★★Create Memory Profile for Unknown Linux Kernel
Analyze `/home/ctfuser/evidence/custom_kernel.dump`, part of the physical memory of a server running an in-house…
Digital ForensicsLevel 5★★★★★Decode Custom Protocol C&C Communication
The egress proxy recorded the traffic of the compromised endpoint 10.20.4.88. In `/challenge/beacon.log`, each line is…