Useful bash scripts compiled during my ethical hacking learning journey

change-mac.bash

#!/usr/bin/env bash
# Change the MAC address of a given interface.
# Usage: sudo ./change-mac.bash <interface name> [<new mac address>]
# Example: sudo ./change-mac.bash wlan0 11:99:22:88:33:77
# Author: @richin13

if [ "$#" -lt 1 ]; then
  echo "Usage: $0 <interface name> [mac address]"
  exit 1
fi

int="$1"
cur_mac="$(ifconfig "$int" | grep ether | xargs | cut -d' ' -f2)"
mac="${2:-00:11:22:33:44:55}"
echo "Changing MAC address for inteface $int from $cur_mac to $mac"
sudo ifconfig "$int" down
sudo macchanger -m "$mac" "$int"
sudo ifconfig "$int" up
echo "[+] Done! Verifying..."
ifconfig "$int" | grep ether | xargs | cut -d' ' -f2

crtsh.bash

#!/bin/env bash
# Read information from crt.sh
# Usage: ./crtsh.bash <domain name>
# Example: ./crtsh.bash example.com
# Author: @richin13
set -e

PREREQUISITES=(curl jq sed sort grep)

for prereq in ${PREREQUISITES[@]}; do
  if [ ! -x "$(command -v "$prereq")" ]; then
    echo "$prereq is not installed"
    exit 1
  fi
done

if [ "$#" != 1 ]; then
  echo "Invalid number of args"
  echo "Usage: $(basename $0) <domain>"
  exit 1
fi

URL="https://crt.sh/?output=json&q=$1"
echo -e "Checking \033[0;36m$URL\033[0m" >&2
curl -s "$URL" | jq -r '.[] | [.name_value] | @csv' | sed 's/"//g' | sort -u | grep -v "*"

find-domain-ips.bash

#!/bin/env bash
# Given a list of domains, retrieve the different IPs associated with those domains
# Usage: ./find-domain-ips.bash <domain name>
# Example: ./find-domain-ips.bash example.com
# Author: @richin13
set -e

PREREQUISITES=(cat dig)

for prereq in ${PREREQUISITES[@]}; do
  if [ ! -x "$(command -v "$prereq")" ]; then
    echo "$prereq is not installed"
    exit 1
  fi
done

if [ "$#" != 1 ]; then
  while read -r domain; do
    dig +short "$domain"
  done | sort -u | grep -Eo '\b([0-9]{1,3}\.){3}[0-9]{1,3}\b'
else
  while read -r domain; do
    dig +short "$domain"
  done < "$1" | sort -u | grep -Eo '\b([0-9]{1,3}\.){3}[0-9]{1,3}\b'
fi

interface-mac.bash

#!/usr/bin/env bash
# Check an interface's MAC address
# Usage: ./interface-mac.bash <interface name>
# Example: ./interface-mac.bash wlan0
# Author: @richin13

function interface-mac() {
  if [ "$#" -lt 1 ]; then
    echo "Usage: $0 <interface name>"
    return 1
  fi
  int="$1"
  ifconfig "$int" | grep ether | xargs | cut -d' ' -f2
}

mon-mode.bash

#!/usr/bin/env bash
# Enable monitor mode in a wireless interface.
# Usage: sudo ./mon-mode.bash <interface name>
# Example: sudo ./mon-mode.bash wlan0
# Author: @richin13

if [ "$#" -lt 1 ]; then
  echo "Usage: $0 <interface name>"
  exit 1
fi

int="$1"
cur_mode="$(iwconfig "$int" | grep Mode | xargs | cut -d' ' -f1 | cut -d':' -f2)"
echo "Enabling monitor mode on $int [Current: $cur_mode]"
sudo ifconfig "$int" down
sudo iwconfig "$int" mode monitor
sudo ifconfig "$int" up
echo "[+] Done! Verifying..."
iwconfig "$int" | grep Mode | xargs | cut -d' ' -f1