Hacking Wireless Networks

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Last updated 3 months ago

Objectives: Understanding Wireless Concepts, understanding wireless encryption algorithms, understanding wireless threats, understanding wireless hacking methodology, wireless hacking tools, understanding bluetooth hacking techniques, understanding wireless hacking countermeasures, overview of wireless penetration testing

Wireless Concepts

  • GSM: universal system used for mobile transportation for wireless network worldwide

  • Bandwidth: Describes amount of information that may be broadcasted over a connection

  • BSSID: The MAC address of an access point that has set up a basic service set

  • ISM band: a set of frequency for the international industrial, scientific, and medical communities

  • Access Point: Used to connect wireless devices to a wireless network

  • Hotspot: Places where wireless network is available for public use

  • Association: Process of connecting a wireless device to an access point

  • Orthogonal Frequency Division Multiplexing: method of encoding digital data on multiple carrier frequencies

  • Direct-Sequence Spread Spectrum: original data signal is multiplied with a pseudo random noise spreading code

  • Frequency-hopping spread spectrum (FHSS): Method of transmitting radio signals rapidly switching a carrier among many frequency channels

  • Wireless Networks

  • WiFi refers to IEEE 802.11 standard

    • SSID (service set identifier)

  • Open System Authentication Process: in open system, any wireless client that wants to access a WiFi networks sends a request to the wireless AP for authentication.

  • Shared Key Authentication Process: in this process, each wireless station receives a shared secret key over a secure channel that is distinct from the 802.11 comm channels.

  • Centralized Authentication server (RADIUS)

    • WiFi Chalking

    • WarChalking: draw symbols in public places to advertise open Wi-Fi networks

    • Types of Wireless Antennas

    • Directional Antennas: Used to broadcast and obtain radio waves from a single direction

    • Omni-Directional Antennas: provides 360 degrees horizontal broadcasts, used in wireless base stations

    • Parabolic Grid Antenna: Based on the idea of a satellite dish. Can pick up Wi-Fi signals ten miles or more

    • Yagi Antenna: unidirectional antenna

    • Dipole Antenna: Bi-Directional Antenna, used to support client connection rather than site-to-site applications

    • Parabolic grid antennas let attackers attack from from farther away (10 miles!)

Wireless Encryption

  • WEP (wired equivalent privacy): weakest encryption. Uses 24-bit initialization vector. A 64 bit WEP uses a 40 bit key etc

  • Can use Cain & Abel to crack

  • WPA (Wifi Protected Access): Stronger encryption with TKIP.

  • You can brute force the keys offline

  • You can defend by using stronger passphrases

  • WPA2: Stronger data protection with AES

  • WPA-2 personal uses a pre-shared key to protect access

  • WPA-2 Enterprise includes EAP or RADIUS for centralized authentication w/kerberos etc

Wireless Threats

  • Access Control Attacks: Aims to penetrate a network by evading WLAN access control measures, such as AP MAC filters and Wi-Fi port access controls

  • Integrity Attacks: Sending forged control management or data frames over a wireless network

  • Confidentiality Attacks: attempt to intercept confidential information sent over wireless associations

  • Availability Attacks: DoS

  • Authentication Attacks: Steal the identity of Wi-Fi clients, their PI, logins, etc. to unauthorized access of network resources

  • Rogue Access Point Attack: Hijacking connections and acting as a middle man sniffing

  • Client Mis-Association: Attacker sets up a rogue access point outside of the corporate perimeter and lures the employees of the organization to connect with it

  • Misconfigured Access Point Attack: Accidents for configurations that you can exploit

  • AD Hoc connection attack: Wifi Clients communicate directly in ad-hoc and do not require AP to relay packet. Attack can attack OS direct since the encryption is weak

  • Honeyspot Access Point Attack: Attacker takes advantage of multiple WLAN’s in area and use same SID

  • AP MAC Spoofing: Hacker spoofs the MAC address of the WLAN client equipment to mask an authorized client

  • Jamming Signal Attack: High gain amplifier

Wireless Hacking Methodology

  1. WiFi Discovery: discovers the WiFi network

  2. GPS Mapping: Attackers create a map of discovered Wi-Fi network and create a database

  3. Wireless Traffic Analysis: identify vulnerabilities, WiFi reconnaissance, Tools for Packet Capture & Analysis

  4. Launch Wireless Attacks

    1. Fragmentation Attack: can obtain 1500 bytes of PRGA data that can be used for injection attacks

    2. Mac Spoofing: attackers change MAC address to that of an authenticated user to bypass the MAC filtering configured in an access point

    3. Denial of Service: Deauthentication and Disassociation attacks

    4. Man in the middle attack MITM : Attacker spoofs his MAC, sends a deAuth requests and then puts himself in the middle

    5. Wireless ARP poisoning attack:

    6. Rogue Access Point: Wireless APs attacker installs on a network without authorization and are not under management of the network administrator. Are not configured with any security

    7. Evil Twin: Replicates another wireless APs name via common SSID

  5. Crack Wi-Fi encryption

    1. Crack WEP using Aircrack

    2. Crack WPA-PSK using aircrack

    3. WEP cracking using Cain & Abel

  6. Compromise the Wi-Fi Network

    • What is spectrum analysis

    • RF spectrum analyzers examine Wi-Fi radio transmissions and measure power (amplitude)

    • Employ statistical analysis to plot spectral usage

    • Can be used for DoS attack

Bluetooth Hacking

  • Exploitation of Bluetooth Stack implementation vulnerabilities

  • Bluesmacking: DoS attack which overflows Bluetooth-enabled devices with random packets causing device to crash

  • Bluejacking: sending unsolicited messages over bluetooth to bluetooth-enabled devices such as mobile phones, laptops, etc

  • Bluesnarfing: Theft of information from a wireless device through a bluetooth connection

    • Blue Sniff: Proof of concept code for a bluetooth wardriving utility

    • Bluebugging: remotely accessing the bluetooth-enabled devices and using its features

    • BluePrinting: collecting information about bluetooth enabled devices such as manufacturer, device model, firmware

    • MAC spoofing attack: intercepting data intended for other bluetooth enabled devices

    • MITM: Modifying data between bluetooth enabled devices communication on a piconet

    • Bluetooth Modes:

    • Discoverable, Limited Discoverable (timed), Non-discoverable

    • Pairing Modes

    • Non-pairable models: rejects every pairing request

    • Pairable mode: will pair upon request

Countermeasures

  • How to defend against bluetooth hacking

    • Use non-regular patterns such as PIN keys

    • Keep device in non-discoverable mode

    • Keep a check of all paired devices

    • Always enable encryptions

Wireless Security Tools

  • Wireless Intrusion Prevention Systems