Page 183 - Cyber Defense eMagazine January 2024

Keywords - Wireless peripheral devices, radio frequency, MouseJack, Crazyradio, wireless keyboards,
USB Dongle, keystrokes, vulnerability, threat.

1. Introduction

Wired mouse and keyboards are no longer used as they are very messy. Today, wireless peripheral
devices are widely preferred as they provide a convenient cable-free connection. However, unlike other
USB devices like memory card readers, MFA authentication devices, USB storage drives, and fingerprint
sensors, wireless mice and keyboards hardly include any security features. Many of these peripherals
are affected by security vulnerabilities which can lead to complete compromise of the computers they are
connected to. As more organizations are supporting remote work, it's very important to understand the
security risks involved when choosing the type of accessories that the employees are allowed to connect
to the workstations.

Wireless peripheral devices like mice and keyboards use proprietary protocols operating in the 2.4GHz
ISM band (Marc Newlin, 2016). They do not follow the Bluetooth protocol which has well-defined industry-
standard security schemas. Thus, the manufacturers end up implementing their own security schemas
which often include weaknesses that can be exploited by malicious users. Wireless mice and keyboards
are paired with a USB dongle that is connected to the computer. The wireless mouse or keyboard
communicates by transmitting radio frequency packets to the USB dongle. When a key is typed on the
keyboard or when the mouse is moved, the packet describing the action performed is transmitted to the
dongle. The dongle listens to these packets and notifies the computer to process and perform the required
actions like moving the cursor or typing the text/commands. To prevent sniffing or eavesdropping, some
manufacturers encrypt the radio frequency packets that are transmitted to the dongle. The decryption
key is stored in the USB dongle using which it can decrypt the data and process the packets. This
prevents attackers from intercepting the data and analyzing the keystrokes transmitted. Also, encryption
lets the wireless devices authenticate to the connected dongle, thus preventing a rouge wireless device
from connecting to the dongle and sending maliciously crafted keystrokes to the computer. However,
most of the wireless peripheral device manufacturers do not encrypt their connection which has allowed
attackers to capture the mouse clicks and keystrokes transmitted. Due to the lack of authentication, the
dongle will not be able to differentiate if the packets are coming from a legitimate peripheral device or
from the attacker. This allows hackers to send malicious keystrokes and mouse clicks to the target
computer. Thus, it is important to evaluate if wireless connections are encrypted and how the dongle
listens to and processes the received commands. Also, if sensitive information is handled it is
recommended not to use wireless peripheral devices regardless of the manufacturers.

2. Wireless Peripheral Devices Security Threats

Wireless peripheral devices like mice and keyboards are affected by various classes of vulnerabilities.
Some of them are described below (Niklas Tomsic, 2022):

2.1 Promiscuous mode nRF24L01+

Cyber Defense eMagazine – January 2024 Edition 183
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