INDEX

Symbols & Numbers

""" (comment) characters, 190

# (comment) character, 83

#! (shebang) characters, 82

--help command, 8–9

-? (help) command, 9

-h (help) command, 8–9

. (execute) command, 84, 90

.. (move up level) command option, 7

/ (forward) command, 26

32-bit/64-bit CPU types, xxv

: (return true) command, 84, 90

[[ (conditional test) command, 91

A

access. See also permissions

network, 31, 32

remote databases, 132–133

restricted internet, 148–149

access lists. See also wordlists, 125

access points (AP), 31, 154, 155–156, 157

Advanced Packaging Tool (apt), 40–44

aircracking suite, 9, 157–159

aireplay-ng command, 159

airmon-ng command, 157–158

airodump-ng command, 158–159

anonymity

IP address tracking, 140–141

with proxy servers, 143–148

with Tor network, 141–143

with VPNs, 148–149

Apache Web Server service, 122–125

apt (Advanced Packaging Tool), 40–45

apt-cache command, 40

apt-get command, 40–43

archiving, 94–96, 115

ARM architecture, xxvi

arrays, 191

at daemon, 69

automount, 106

B

background processes, 68–69

backup scheduling task, 176–177

bad blocks table, 108

banner-grabbing, 194–195, 199–201

banners, 194

bash (Bourne-again shell)

common commands, 90–91

overview, 2, 4, 72, 82

Bcast (broadcast address), 30

bg (background) command, 90

/bin directories, 5, 76

binaries

defined, 2

in Linux filesystem, 5

search commands, 10

BIND (Berkeley Internet Name Domain), 34

black hat hackers, 86

block devices, 105–106

Bluetooth, 159–164

overview, 159–160

scanning, 160–164

Bluetooth SIG site, 162

BlueZ protocol stack, 160–161

bootloader, xxxiv

break command, 90

broadcast address

changing, 32

information, 30

broadcast command option, 32

BSSID (basic service set identifier), 154, 158–159

bunzip2 command, 97

Butler, Max “Max Vision”, 86–87

bzip2 command, 97

C

case sensitivity, 2

cat (concatenation) command, 13–14, 22, 167

cd (change directory) command, 7

channels (CH), Wi-Fi, 154, 158, 158–159

character devices, 105

chgrp (change group) command, 51

chmod (change mode) command, 52–55, 56, 58

chown (change owner) command, 50

classes and subclasses, 193–194

command directories, 76–77

command line interface (CLI), 2

comment characters, 83, 190

compress command, 97

compression, 93–94, 96–97

concatenation, 13–14, 22, 67

configuration files, 5

connect method, 194–195

continue command, 90

control statements, 197–199

copy commands

bit by bit, 98–99

file, 15

cp (copy file) command, 15

CPU types, xxv

createuser command, 137

cron daemon, 174

cron table, 174–178

crond command, 69, 174

crontab command, 175–176

D

daemons, 32, 69

dark web, 142

databases. See also MySQL databases

hacking, 87, 130

db_status command, 137

dd command, 98–99

Debian distribution, xxv

deleted file copy, 98–99

denial-of-service (DoS) attacks, 31

describe command, 134

/dev directory, 102–106

device drivers, as hacking target, 171

df (disk free) command, 107–108

dhclient command, 33

dhcp daemon, 32

DHCPDISCOVER request, 33

DHCPOFFER request, 33

DHSCP servers, 32–33, 35

dict statement, 197

dictionaries, 197

dig command, 33–34

directories. See also filesystems

changing, 7

creating, 15

Linux filesystem, 5

listing content, 7–8, 51–52

naming, 2

and PATH variable, 76–77

permissions, 51–52

present working, 6

removing, 16

searching, 11–12

disk space, xxix, 107–108

dmesg command, 171

DNS (Domain Name System), 33–35

changing servers, 34–35

information, 33–34

E

eavesdropping, 150, 166

echo command, 35, 83, 90

email encryption services, 150

encryption

email, 150

with VPNs, 149

wireless security (ENC), 158

env (environment) command, 72

environment variables. See also shell variables

changing values, 73–74

command directories, 76–77

concepts, 71–72

shell prompt, 75–76

user-defined, 77–78

viewing, 72–73

espionage, xxiii, 141, 148, 149

ESSID (extended service set identifier), 154, 158–159

/etc/apt/sources.list file, 44

/etc/crontab file, 174–176

/etc directory, 5

/etc/fstab file, 107

/etc/hosts file, 36

/etc/init.d/rc file, 179

/etc/logrotate.conf file, 115–117

/etc/proxychains.conf file, 144

/etc/resolv.conf file, 34–35

/etc/rsyslog.conf file, 112–115

/etc/shadow file, 57

/etc/sysctl.conf file, 167, 168

eth0 interface, 30

ethical hacking, xxii–xxiii

eval (evaluate expression) command, 90

exception handling, 201

exec command, 90

execute permissions, 55–56, 57–58, 83–84

exit command, 90

exploits, 196–197

export command, 74, 75–76, 90

F

fdisk utility, 104

fg (foreground) command, 69, 90

file content. See text

file types, 104–105

files. See also log files; text

archiving, 94–96

compressing, 96–97

copying, 15, 97–98

creating, 13–15

listing, 7–8, 51–52

moving, 15–16

naming, 2

ownership, 50–51

removing, 16

renaming, 15–16

searching for, 10–12

filesystems

Linux structure, 4–5

monitoring, 107–109

navigating, 6–8

searching, 9–12

storage devices in, 102–106, 107

filtering with keywords, 12–13, 22–23, 63–64, 73

find command, 11–12, 59

flash drives, 104–105, 106

for loop, 199

frequency, Wi-Fi, 154

fsck (filesystem check) command, 108–109

ftplib module, 201–202

G

getopts command, 91

git clone command, 46–47

github, 46

Google internet tracking, 140

Grand Unified Bootloader (GRUB), xxxiv–xxxv

gray hat hackers, 86–87

grep command, 12–13, 22, 24, 63, 73

GRUB (Grand Unified Bootloader), xxxiv–xxxv

gzip command, 96–97

H

hacking

malicious, 86–87

as profession, xxi–xxiii

and scripting skills, 183

hard drive partitions, xxxiii

hciconfig command, 161

hcidump command, 161

hcitool command, 161–162

head (view file) command, 20–21, 23

help commands, 8–9

hidden file switch, 8

history file size, 73–74

HISTSIZE (history file) variable, 73

home directory, 2, 5

hosts file, 36

html code example, 124–125

HTTP vs. Torrent, xxv–xxvi

HWaddr. See MAC address

I

IDEs (integrated development environments), 187

if statement, 197–198

ifconfig command, 29–30, 31–32, 154–155

if...else statement, 198

import statement, 192

index.html file, 124–125

init daemon, 179

insmod (insert module) suite, 169

IP forwarding, 168–169

IP (Internet Protocol) addresses

analyzing, 29–30

changing, 31

domain name mapping, 36

requesting new, 32–33

scanner script, 87–88

tracking, 140–141

.iso file extension, xxx

iterable lists, 191

iwconfig command, 30–31, 155, 157

iwlist command, 155–156

J

job scheduling, 173–178

jobs command, 91

K

Kali

desktop, 3–5

downloads, xxv–xxvi

installation, xxix–xxxi

login, xxxv–xxxvi

overview, 2

setup, xxxi–xxxv

kernel, 62, 165–166, 167–169

kernel modules. See also loadable kernel modules, 166, 169–171

KEY statements, 72

kill command, 67–68

kill signals, 67

killall command, 67–68

L

l2ping command, 163–164

LAMP tools, 123

less command, 25–26

/lib directory, 5

libraries, 5

Linux

advantages of, xxiv

case sensitivity, 2

distributions, xxv

runlevels, 179

LKMs. See loadable kernel modules (LKMs)

lo (loopback address) information, 30

loadable kernel modules (LKMs). See also kernel modules, 166, 169–171, 171–172

localhost, 30

locate command, 10

log files, 115–118

rotating, 115–117

shredding, 117–118

logging systems

concepts, 111

configuration and rules, 112–115

disabling, 118–119

login checking, 6

logrotate utility, 115–117

loopback address, 30

loops, 198–199

lossy vs. lossless compression, 94

ls (list) command, 7–8, 51–52

lsblk (list block) command, 105–106

lsmod (list modules) command, 169

M

MAC address

displaying, 30, 156

spoofing, 32

man-in-the-middle (MITM) attacks, 166, 168

man (manual) command, 9, 23

managed mode, 31

manual pages, 9

Mask information, 30

master mode, 155

/media directory, 5, 106–107

message logging. See logging systems

Metasploit, 63, 136–137

methods, 193–194, 195

military hacking, xxiii

MITM (man-in-the-middle) attacks, 166, 168

mkdir (make directory) command, 15

/mnt directory, 5, 106

mobile devices, xxiv–xxv, xxvi

modinfo command, 170

modprobe command, 169, 170–171

monitor mode, 155, 157–158

more command, 25

mount points, 106

mounting/unmounting devices, 106–107

mv (move/rename) file command, 16

MySQL/MariaDB databases, 130–135

accessing, 132–133

connecting to, 133–134

information, 131–132

tables, 134–135

MySQL Scanner script

code example, 87–90

scheduling, 177–178

mysql service, 130–135

N

nameservers, 33–35

National Security Agency (NSA), 139, 143

netmask command option, 32

network cards, 155, 157

network connection scripts, 194–197

network intrusion detection system (NIDS), 19

network manager, 156

network mask

changing, 32

display, 30

networks. See also Wi-Fi networks

analyzing, 29–31

changing information, 31–33

nfnetlink module, 169

nice (process priority) command, 65–66

NIDS (network intrusion detection system), 19

nl (number lines) command, 22, 23

nmap (network map) command, 86, 87–88

nmcli (network manager command line interface) command, 156

O

object-oriented programming (OOP), 192–194

objects, 193–194, 195

octal digits, 53

.onion addresses, 142

Onion Router system, 141–143

OOP. See object-oriented programming (OOP)

open source code, xxiv, xxv

OpenSSH service, 125–126

P

packet forwarding, 168–169

pairing Bluetooth, 160

partitions

defined, xxxiii

labeling system, 103–104

passwd command, 4

passwords

changing, 4

cracking, 31, 159, 201–203

root user, xxxii–xxxiii, 132–133

PATH variable, 76–77

penetration testing, xxiii

permissions, 49–59

changing, 52–57

checking, 51–52

concepts, 49–50

granting, 50–51, 83–84

special, 57–59

PID (process ID), 62, 63

pip (Pip Installs Packages) manager, 184–185

piping, 12–13

ports

banner-grabbing script, 199–201

connecting to, 194–195

scanning, 86–90

PostgreSQL (Postgres) databases, 135–137

postgresql service, 136–137

power (PWR) and Wi-Fi, 154, 158, 158–159

priority

message logging, 114–115

processes, 64–66

privilege escalation, 58

/proc/version file, 167

process ID (PID), 62, 63

processes, 61–69

background and foreground, 68–69

concepts, 61–62

information on, 12–13, 62–64

killing, 66–68

managing priority of, 64–66

scheduling, 69

.profile file, 57

promiscuous mode, 31

properties, 193

ProtonMail, 150

proxy servers, 143–148

choosing, 148

concepts, 143–144

setting up, 144–148

proxychains command, 143–148

ps (processes) command, 12–13, 62–63

PS1 (shell prompt) variable, 75–76

PSK (pre-shared key), 154

pwd (present working directory) command, 6

Python language

comments, 190

functions, 190–191

installing, 184–186

learning, 183–184, 187, 203

lists, 191–192

modules, 192

variables, 187–190

Python Package Index (PyPI), 184

R

Raspberry Pi

architecture, xxvi

Spy project, 125–129

Raspbian operating system, 126, 129

raspistill application, 129

rc scripts, 178–180

rcconf tool, 180–181

read command, 85, 91

readonly command, 91

reconnaissance, 160–164, 197

renice command, 65, 66

repositories, 40, 43–44, 185

resource usage, 64

rm (remove) command, 16

rmdir (remove directory) command, 16

rmmod (remove module) command, 169

/root directory, 5

root user

defined, 2

passwords, xxxii–xxxiii, 131, 132

privileges, 5, 6, 50, 65, 66

rootkits, 166, 171

rsyslog daemon, 112, 119

runlevels, 179

S

/sbin directories, 76

scheduling

with at, 69

with crond, 174–178

at startup, 178–181

script variables, 84–85, 89

scripts

concepts, 2, 81

examples, 86–90

executing (running), 83–84

scheduling, 174–178

writing, 82–85

SDP (Service Discovery Protocol), 163

sdptool command, 163

security. See also permissions

and loadable kernel modules, 171–172

and surveillance, 142–143, 148, 149

Wi-Fi protocol, 154

sed (stream editor) command, 24

SELECT command, 135

service command, 119, 122

Service Discovery Protocol (SDP), 163

services

defined, 121

scheduling at startup, 179–181

starting, stopping, restarting, 122

set command, 72–73, 91

SGID bit, 58–59

.sh file extension, 85

shebang (#!), 82

shell prompt, 75–76

shell variables, 71–72

shells, 2, 82

shift command, 91

show command, 134

shred command, 117–118

Snort, 19–20, 21

socket module, 194–196

software managers and installers, 40, 45–46

software packages

defined, 39

installing, 40–41

removing, 41–42

updating and upgrading, 42–43

sources.list file, 43–44

spy camera project, 125–129

SQL (Structured Query Language) commands, 131

SSH (Secure Shell), 125–126

SSID (service set identifier), 154

sticky bit permission bit, 58

storage devices, 102–109

monitoring and checking, 107–109

mounting and unmounting, 106–107

representation of, 102–106

strip() function, 202

su (switch user) command, 136

SUID bit, 57–59

surveillance concerns, 142–143, 148, 149

Synaptic Package Manager, 45–46

sysctl command, 167–169

syslogd daemon, 112

system administrator. See root user

T

tail (view file) command, 21–22, 23

tar (archive) command, 94–96

.tar file extension, 95

tarballs/tar files, 94–96

TCP client script, 194–195

TCP connect scan, 86, 88–90

TCP listening script, 195–197

terminals, 2, 4, 68

test command, 91

text

concatenating to file, 13–14

displaying, 20–23, 24–26

find and replace, 23–24

text editors, 82, 187

.tgz file extension, 96

times command, 91

top (resource usage) command, 64, 66

Tor network, 141–143

torrent downloads, xxv–xxvi

touch command, 14–15

traceroute command, 140

trap command, 91

try/except statements, 201–202

type command, 91

U

UGO (user, group, and others) syntax, 54–55

umask (unmask) values, 56–57, 91

umount (unmount) command, 107

uname command, 167

uncompress command, 97

unset command, 72–73, 78, 91

update-rc.d command, 179

USB flash drives, 104–105, 106

use command, 134

user-defined variables, 77–78

user land, 165

user types, 50

V

variables. See also environment variables

Python, 187–190

script, 84–85, 89

shell, 71–72

virtual machines, concepts and installation, xxvi–xxvii

virtual private networks (VPNs), 148–149

VirtualBox

installation and setup, xxvi–xxix

installing Kali on, xxix–xxxi

virtualization software, xxxi

VPNs (virtual private networks), 148–149

vulnerability assessments, xxiii

W

wait command, 91

web server services, 122–125

WEP (Wired Equivalent Privacy) protocol, 154

wget command, 185–186

whereis command, 10

which command, 10

while loops, 198

white hat hacking, xxiii

whoami command, 6

Wi-Fi networks, 154–159

basic commands, 154–157

hacking, 157–159

wildcards, 12

Windows vs. Linux, xxiv–xxv, 101

wireless network devices, 30–31, 153

wireless range, 154

wlan0 interface, 30, 31, 155

wordlists, 27, 159, 202

WPA (Wi-Fi Protected Access) protocol, 154

WPA2-PSK protocol, 154

Z

zombie processes, 66, 67