Kali Linux - Basics

:ID: cb51a9d3-842b-4b10-ae56-2d18573b5f3e

:END:

Filesystem

FHS - Filesystem Hierarchy Standard - conventions used for layout of a UNIX system LinuxFoundation

/bin : basic programs like ls, cd, cat
/sbin : system programs like fdisk, makefs, sysctl
/etc : configuration files bk
/tmp : temporary files, typically deleted on boot
/usr/bin : applications like apt, ncat, nmap
/usr/share : application support and data files

Basic Linux commands

Finding files

`which`

searches through directories in the $PATH environment variable for a given file name; returns the full path to the file if a match is found

locate

quickest way; uses locate.db, database updated regularly by cron scheduler; update manually with sudo updatedb

find

most complex and flexible; eg recursive search starting from root of filesystem, searching for any files that start with sbd: sudo find / -name sbd*; find can search by many attributes

Ex: find files modified in last day and not owned by root; execute ls -l on them:

find / -mtime -1 -type f ! -user root -exec ls -l {} \;

Ex: find files of a certain size and base64 decode contents

find / -size 64c -exec base64 -d {} \; 2>/dev/null

man pages

Manual content divided into sections:

Section	Contents
1	User Commands
2	Programming interfaces for kernel system calls
3	Programming interfaces to the C library
4	Special files such as device nodes and drivers
5	File formats
6	Games and amusements
7	Miscellaneous
8	System administration commands

Name, synopsis, description, along with options, parameters, switches, etc

man cat

Search by Keyword

man -k '^passwd$' – search by regex

Search using `apropos`

search descriptions, equivalent to man -k

Kali services

In order to maintain a low profile, Kali prevents network services from starting by default – they need to be specifically enabled

ssh

sudo systemctl start ssh

Verify:

sudo ss -antlp | grep sshd

To start automatically at boot: sudo sytemctl enable ssh

http

http service (apache) – hosting a site or a platform for downloading files to victim machine

sudo systemctl start apache2

List of all available services

systemctl list-unit-files

Tools

apt is the package manager for this debian-based system

apt uses

– apt update ; apt upgrade – apt-cache search apt-cache search pure-ftpd – apt show – apt install

dpkg

does not require an internet connection; will not install dependencies