MAC adress spoofing automatic

#1

Hi there,
as the world devolops as in “1984”, it may be a good idea to spoof your MAC adress. Here is how:

first we need to know the interfaces:
ip link show
There may be an ethernet like enp0s25 as well as a WiFi interface like wlp3s0. After installing macchanger
pacman -S macchanger
shut down your interfaces, to check if it worked without rebooting:
ip link set wlp3s0 down && ip link set enp0s25 down
Then, create a service:
touch /etc/systemd/system/macspoof@.service
Edit / copypaste the file as follows:

[Unit]
Description=macchanger on %I
Wants=network-pre.target
Before=network-pre.target
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
ExecStart=/usr/bin/macchanger -r %I
Type=oneshot

[Install]
WantedBy=multi-user.target

Enable the service for your interfaces immediatly and with every reboot
systemctl enable --now macspoof@enp0s25.service && systemctl enable --now macspoof@wlp3s0.service
Bring up your interfaces
ip link set enp0s25 up && ip link set wlp3s0 up
and see if MAC changed with
ip link show

Voila!
You may want to have a script to cange mac without rebooting:

#! /usr/bin/env sh
ip link set enp0s25 down
ip link set wlp3s0 down
systemctl restart macspoof@enp0s25.service
systemctl restart macspoof@wlp3s0.service
ip link set enp0s25 up
ip link set wlp3s0 up
exit 0

#2

Thx for sharing @entr0py . Top work in there.

#3

Absolute top marks @entr0py

#4

Glad you like it. But even easyer to have a script doing all the steps, once run. Here you go:

#! /usr/bin/env sh
if [ "$EUID" -ne 0 ]
then 
	echo "Please run as root! Exit."
	exit 1
fi
# Checking for macchanger
echo "This script will assign a random MAC adress for each interface immediatly and on every reboot."
echo "Checking for macchanger..."
macchanger &> /dev/null
if [ $? == 0 ]
then
	echo "success!"
elif [ $? != 0 ]
then
	read -p "Negative. Install it? (y) to continue " -n 1 -r
	echo
	if [[ $REPLY =~ ^[Yy]$ ]]
	then
		pacman -S macchanger
		#UNDO01="pacman -Rs macchanger"
	else
		echo "Exit"
		exit 1
	fi
fi


# Write service file

echo "Creating service: /etc/systemd/system/macspoof@.service"
cat > /etc/systemd/system/macspoof@.service << EOF
[Unit]
Description=macchanger on %I
Wants=network-pre.target
Before=network-pre.target
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
ExecStart=/usr/bin/macchanger -r %I
Type=oneshot

[Install]
WantedBy=multi-user.target
EOF
#UNDO02="rm /etc/systemd/system/macspoof@.service"

# Determine interfaces and start service
echo "Start service for each interface..."
INTERFACES="$(awk '{print $1}' /proc/net/dev|grep :|sed "s/:.*//g")"
for INTERFACE in $INTERFACES; do
	if [ $INTERFACE != "lo" ]
	then
		echo "Interface: "$INTERFACE"..."
		ip link set $INTERFACE down
		systemctl enable --now macspoof@$INTERFACE.service
		ip link set $INTERFACE up
	fi
done

#creating command changemacs
cat > /usr/bin/changemacs << EOF
#! /usr/bin/env sh
if [ "\$EUID" -ne 0 ]
then 
	echo "Please run as root! Exit."
	exit 1
fi
INTERFACES="\$(awk '{print \$1}' /proc/net/dev|grep :|sed "s/:.*//g")"
for INTERFACE in \$INTERFACES; do
	if [ \$INTERFACE != "lo" ]
	then
		ip link set \$INTERFACE down
		systemctl enable --now macspoof@\$INTERFACE.service
		ip link set \$INTERFACE up
	fi
done
exit 0
EOF
chmod +x /usr/bin/changemacs
echo "Run 'changemacs' to assign random MAC adresses for each interface immediately."
#5

Even better @entr0py . Keep up the great work. Danke.

#6

Nice guide, thanks!

A few notes for your script:

It may be better to use pacman -Syu macchanger to ensure all of the libraries match. See this post for an example of a package failure after using pacman -S alone.

However, some prefer to backup before full system upgrades (in case of b0rkage) so this is far from clear-cut.

Also:

The grep & sed can be dropped and the search & filter added to awk instead:

INTERFACES="$(awk -F":" '/:/{print $1}' /proc/net/dev)"

We don’t need no stinkin’ pipes :slight_smile:

#7

Thank you very much sir, will Update tomorrow!