/intro-linux-ctf

Introduction to Linux CTF developed for UAF CSC Lecture.

Primary LanguageShell

intro-linux-ctf

Introduction to Linux CTF

  • Shells

    • Bash
      • .bash_profile
    • zsh
      • .zsh_profile

  • Navigation

    • ls
    • pwd
    • cd

  • Editing

    • mv
    • cp
    • mkdir
    • touch
    • rm
    • nano
    • vim
    • cat
    • less
    • head
    • tail

  • Users & Permissions

    • who
    • su
    • sudo
    • usermod
    • chmod
    • getent passwd (/etc/passwd)
    • getent group
    • User-Group-Everybody

  • Processes

    • ./
    • which
    • top
    • ps
    • kill

  • Networking

    • netstat
    • ifconfig

  • Remote Connections

    • ssh
    • scp

Challenges:

  • 1 pt:

    • "Ain't too Tabby"
      • cd into a long folder name using tab completion and ls to see the key
    • "In Plain Sight"
      • Use ls -lah to see a hidden file
    • "She Sells Z Shells"
      • Switch to using zsh
    • "Heads or Tails?"
      • Use tail to show the end of a super long file where the key is hidden

  • 3 pt:

    • "Outsourced"
      • Edit the .bash_profile to uncomment a line and source it for the key to show
    • "who?"
      • Find a hidden user that is the key
    • "I command thy"
      • Use sudo to run a c++ executable hidden in the folders
    • "A lot to process"
      • Use ps to find a running process that is the key

  • 5 pt:

    • "Freaky Friday"
      • Find a user on the system named something suspicious and switch to their account using su
    • "Which witch?"
      • "We have reason to suspect someone tampered with a critical command on the system. See if you can find out which one."
      • Have a wrapper around ls that overloads the command and secretly records the output to a directory and runs from "/etc/nginx/sites-enabled/this_is_definitely_not_suspicious/ls" and have the key
    • "Locked out"
      • Use sudo to change the permissions on a python script with 000 permissions and then use nano to edit it and uncomment a line and then execute it to reveal the key

  • 10 pt:

    • "King of the Box"
      • user: csc_ctf password: sUp3r_uNh4cKaBl3_4nD_s3cUr3
      • The key is hidden on this box and must be ssh'd to