Linux Commands for Hackers

Security work runs on Linux, and the commands that matter most are not the flashy ones. They are file navigation, the permission model, process control, networking checks and text processing with grep, awk and sed. Master those and you can improvise in an engagement instead of copying from a cheat sheet.

Why these specifically

You will not follow a tutorial during a real engagement. You will be on a compromised host, improvising. These are the commands you reach for without thinking, grouped by what they do.

File system and navigation

ls -la          list all, long format
cd /path        change directory
find / -name x  find files by name
locate x        fast filename search
cat, less, head, tail   read files

Permissions, the one that matters for hacking

Linux privilege escalation is almost entirely about the permission model. Know these cold:

chmod, chown    change permissions and ownership
find / -perm -4000 2>/dev/null   find SUID binaries
sudo -l         what can this user run as root
id              current user and groups

That SUID find command is one of the first things you run after landing on a host. Detail in Linux privilege escalation.

Processes and services

ps aux          all running processes
top / htop      live process view
kill, pkill     stop a process
systemctl       manage services
crontab -l      scheduled jobs

Networking

ip a            interfaces and addresses
ss -tulpn       listening ports and processes
curl, wget      fetch over HTTP
nc              netcat, the swiss army knife

Text processing, the force multiplier

Parsing output fast separates slow testers from fast ones.

grep 'pattern' file       search
cat file | grep x | wc -l  count matches
awk '{print $1}'          extract columns
sed 's/a/b/g'             find and replace
cut -d: -f1 /etc/passwd    extract fields

Finding credentials and secrets

grep -r 'password' /var/www 2>/dev/null
find / -name '*.conf' 2>/dev/null
history

How to actually learn these

Do not memorise a cheat sheet. Install Linux, use the terminal for everything, and learn each command when a task needs it. Fluency comes from living in it. Full approach in how to learn Linux for hacking.

Practise this

Attack and escalate on real Linux machines. Free targets on Hacklido.