Signal9 Blog
Hands-on Linux security: incident response walkthroughs, hardening labs, and seasonal CTF write-ups — on real systems, graded on machine state.
Train on Signal9 →C2 Beacon Hunt Lab: Hands-On Linux Incident Response Practice
Walk through a real C2 beacon hunt lab on a live root terminal — hands-on DFIR training graded on the state of the machine, not a flag. Free Linux incident response practice from Signal9.
Linux CTF Archive — seasonal forensics & DFIR challenges
Hands-on capture-the-flag seasons on real Linux systems; past seasons ship with full write-ups.