Challenge list
General SkillsLevel 2★★☆☆☆Compression Maze - Nested Archives
/app/flag.tar.gz is a nested compressed file. Decompress step by step: flag.tar.gz → flag.tar → flag.zip.bz2.gz →…
CryptographyLevel 2★★☆☆☆Breaking Small RSA Keys
Factor a tiny RSA modulus, recover the private exponent, and decrypt a list of ciphertext values. Public key and…
CryptographyLevel 2★★☆☆☆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…
General SkillsLevel 2★★☆☆☆Regex Master - Log File Analysis
The file /app/access.log contains thousands of access log entries. Extract all entries where the IP address starts…
General SkillsLevel 2★★☆☆☆Environment Variable Master - PATH Hijacking
There is a hidden command "getflag" in /app/secret_bin directory. However, this directory is not in PATH, so you…