privacy-guides/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/README.md

How to spoof (anonymize) your MAC address and hostname automatically at boot on macOS

Heads up: unfortunately this guide does not work on Macs equipped with the new T2 chip running macOS Mojave. If that’s your case, please consider upgrading to Catalina.

Step 1: create /usr/local/sbin folder

sudo mkdir /usr/local/sbin
sudo chown $(whoami):admin /usr/local/sbin/

Step 2: create spoof.sh script

Pro tip 1: when copy/pasting commands that start with cat << "EOF", select all lines (from cat << "EOF" to EOF) at once as they are part of the same (single) command

cat << "EOF" > /usr/local/sbin/spoof.sh
#! /bin/sh

set -e

export LC_CTYPE=C

dirname=`dirname "${BASH_SOURCE}"`

# Spoof computer name
model_name=`system_profiler SPHardwareDataType | awk '/Model Name/ {$1=$2=""; print $0}' | sed -e 's/^[ ]*//'`
first_name=`sed "$(jot -r 1 1 2048)q;d" $dirname/first_names.txt | sed -e 's/[^a-zA-Z]//g'`
computer_name=`echo "$first_name’s $model_name"`
host_name=`echo $computer_name | sed -e 's/’//g' | sed -e 's/ /-/g'`
sudo scutil --set ComputerName "$computer_name"
sudo scutil --set LocalHostName "$host_name"
sudo scutil --set HostName "$host_name"
echo "Spoofed hostname to $host_name"

# Spoof MAC address of en0 interface
mac_address_prefix=`sed "$(jot -r 1 1 768)q;d" $dirname/mac_address_prefixes.txt | sed -e 's/[^A-F0-9:]//g'`
mac_address_suffix=`openssl rand -hex 3 | sed 's/\(..\)/\1:/g; s/.$//'`
mac_address=`echo "$mac_address_prefix:$mac_address_suffix" | awk '{print toupper($0)}'`
sudo ifconfig en0 ether "$mac_address"
echo "Spoofed MAC address of en0 interface to $mac_address"
EOF

Ok, a lot is happening here. Let’s break it down into reviewable pieces.

set -e

Exit on error

export LC_CTYPE=C

Fix sed: RE error: illegal byte sequence sed error

dirname=`dirname "${BASH_SOURCE}"`

Set variable dirname to path of spoof.sh

model_name=`system_profiler SPHardwareDataType | awk '/Model Name/ {$1=$2=""; print $0}' | sed -e 's/^[ ]*//'`

Set variable model_name to the model of your Mac

first_name=`sed "$(jot -r 1 1 2048)q;d" $dirname/first_names.txt | sed -e 's/[^a-zA-Z]//g'`

Set variable first_name to random first name found in first_names.txt

computer_name=`echo "$first_name’s $model_name"`
host_name=`echo $computer_name | sed -e 's/’//g' | sed -e 's/ /-/g'`

Set variables computer_name and host_name using values from variables first_name, model_name and computer_name

sudo scutil --set ComputerName "$computer_name"
sudo scutil --set LocalHostName "$host_name"
sudo scutil --set HostName "$host_name"
echo "Spoofed hostname to $host_name"

Set ComputerName, LocalHostName and HostName using scutil and echo spoofed computer name

mac_address_prefix=`sed "$(jot -r 1 1 768)q;d" $dirname/mac_address_prefixes.txt | sed -e 's/[^A-F0-9:]//g'`

Set variable mac_address_prefix to random Apple MAC address prefix found in mac_address_prefixes.txt

mac_address_suffix=`openssl rand -hex 3 | sed 's/\(..\)/\1:/g; s/.$//'`

Set variable mac_address_suffix to random value genereated by OpenSSL

mac_address=`echo "$mac_address_prefix:$mac_address_suffix" | awk '{print toupper($0)}'`

Set variable mac_address using values from variables mac_address_prefix and mac_address_suffix and convert to upper case

sudo ifconfig en0 ether "$mac_address"
echo "Spoofed MAC address of en0 interface to $mac_address"

Set spoofed MAC address using ifconfig and echo spoofed MAC address

Step 3: make spoof.sh executable

chmod +x /usr/local/sbin/spoof.sh

Step 4: download first_names.txt

This list includes the top 2048 most popular baby names from the USA Social Security Administration.

curl -o /usr/local/sbin/first_names.txt https://sunknudsen.com/static/media/privacy-guides/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/first_names.txt

Step 5: download mac_address_prefixes.txt

This list includes 768 Apple MAC address prefixes.

curl -o /usr/local/sbin/mac_address_prefixes.txt https://sunknudsen.com/static/media/privacy-guides/how-to-spoof-anonymize-your-mac-address-and-hostname-automatically-at-boot-on-macos/mac_address_prefixes.txt

Step 6: create local.spoof.plist launch daemon

This step is responsible for running spoof.sh every time your Mac boots.

cat << "EOF" | sudo tee /Library/LaunchDaemons/local.spoof.plist > /dev/null
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>Label</key>
        <string>spoof.sh</string>

        <key>ProgramArguments</key>
        <array>
            <string>/usr/local/sbin/spoof.sh</string>
        </array>

        <key>RunAtLoad</key>
        <true/>
    </dict>
</plist>
EOF

Step 7: reboot and confirm hostname and MAC address have been spoofed

# Spoofed hostname
scutil --get HostName

# Spoofed MAC address
ifconfig en0 | grep ether | awk '{print $2}'

# Hardware MAC address
networksetup -listallhardwareports | awk -v RS= '/en0/{print $NF}'

"Spoofed hostname" is random and "Spoofed MAC address" doesn’t match "Hardware MAC address"?

👍

---

Want things back the way they were before following this guide? No problem!

Step 1: set computer name, local hostname and hostname

Replace John Doe with a value to your liking. Don’t forget to replace empty spaces by - for LocalHostName and HostName.

sudo scutil --set ComputerName "John Doe"
sudo scutil --set LocalHostName "John-Doe"
sudo scutil --set HostName "John-Doe"

Step 2: set MAC address to factory value

Given MAC address spoofing is ephemeral, deleting the /Library/LaunchDaemons/local.spoof.plist launch daemon and rebooting will reset your MAC address to its factory value.

sudo rm /Library/LaunchDaemons/local.spoof.plist

Step 3 (optional): delete script and datasets

rm /usr/local/sbin/spoof.sh
rm /usr/local/sbin/first_names.txt
rm /usr/local/sbin/mac_address_prefixes.txt