Challenge list
Breaking Small RSA Keys
Factor a tiny RSA modulus, recover the private exponent, and decrypt a list of ciphertext values. Public key and…
Cryptanalysis - Breaking the Affine Cipher
ciphertext.txt is an English report encrypted with the affine cipher E(x) = (a*x + b) mod 26. Letter case is preserved…
Message Hidden in Image LSB
Extract the message hidden in the LSB (Least Significant Bit) of a PNG file. Learn the basics of steganography…
Extract Session Cookies from Chrome
You are given `/challenge/Cookies` and `/challenge/History` (both SQLite) taken from a Linux Chrome profile. The…
Detect DNS Tunneling
Analyze the DNS query log `dns_queries.log` to detect data exfiltration via DNS tunneling. Find the host flooding a…
Find Deleted File Traces in NTFS $MFT
You are given `/challenge/mft_records.txt`, the `$MFT` of the Windows machine `KINOCO-WS07` written out as per-record…
Detect Brute-Force Attack in Event Logs
Analyze the sshd authentication log `/challenge/auth.log` of the server `kinoco-srv01` and identify the session of the…
Find Suspicious Network Connections in Memory
From the memory image of the compromised host `kinoco-app03`, the socket table `/challenge/netstat_dump.txt` and the…
Recover Executed Commands from Memory
Analyze the memory-string record `memdump.txt` to recover the executed command history. Decode the Base64 strings and…
Recover Deleted SQLite Records
You are given the SQLite database `/challenge/app.db` of the internal chat tool "kinoco-msg". The body of a message…
Decompress Multi-Layer Archive
`/challenge/artifact.xz` is a file an attacker tried to take out, wrapped many times in gzip, bzip2, xz, zip and tar.…
Decrypt Encrypted Disk
`/challenge/secret_disk.img` is a genuine LUKS2 container. Its data area holds a backup (a tar archive). The…
Cryptanalysis - RSA Common Modulus Attack
Two systems reused the same RSA modulus n and only changed the public exponent. The ciphertexts c1 and c2 of the same…
Cryptanalysis - Diffie-Hellman with a Small Prime
An old IoT device performed Diffie-Hellman key exchange with a prime p of only 36 bits. handshake.txt contains p, g, A…
Data Hidden in Audio File
`hidden.wav` hides a message encoded with on-off keying (OOK). Turn the tone on/off slots into bits and decode them to…
Extract Secret Key from Android App
Extract a safe ZIP-formatted APK fixture (evidence/app.apk) and analyze the encrypted API secret recorded in its…
Detect Unauthorized Access in CloudTrail Logs
Analyze the CloudTrail export `/challenge/cloudtrail.json` and trace the unauthorized use of a stolen access key and…
Extract Secrets from Docker Image Layers
`/challenge/image/` is an unpacked `docker save` export (OCI layout). The layers are stored in `blobs/sha256/` as…
Decrypt TLS-Encrypted HTTPS Traffic
In `~/evidence/` there is a capture `traffic.pcap` (libpcap format) of HTTPS traffic from a client PC, and the TLS key…
Extract Malware Payload from Memory
`/challenge/memstrings.txt` holds the strings extracted from the address space of a suspicious process, and the…
Detect Hidden Kernel Module in Memory
From the memory of a Linux host suspected of an LKM rootkit infection, three sets of module information were…
Decode Multi-Stage Steganography
Three stages of steganography are planted in `/challenge/cover.png` and `/challenge/notes.txt`. Each stage holds the…
Recover Fragmented JPEG File
`/challenge/fragments/` holds 256-byte clusters (`clus_NNNN.bin`) recovered from the unallocated space of a memory…
Cryptanalysis - DSA Nonce Reuse Key Recovery
/challenge/signatures.json, created with fresh keys at every start, holds the DSA public parameters (p of 1024 bits, q…