|Data Sources||Network protocol analysis, Packet capture, Network intrusion detection system|
|External Contributors||Scott Dougherty|
|Asset||Control Server, Field Controller/RTU/PLC/IED, Input/Output Server|
Adversaries may perform wireless compromise as a method of gaining communications and unauthorized access to a wireless network. Access to a wireless network may be gained through the compromise of a wireless device.12 Adversaries may also utilize radios and other wireless communication devices on the same frequency as the wireless network. Wireless compromise can be done as an initial access vector from a remote distance.
A joint case study on the Maroochy Shire Water Services event examined the attack from a cyber security perspective.3 The adversary disrupted Maroochy Shire's radio-controlled sewage system by driving around with stolen radio equipment and issuing commands with them. Boden used a two-way radio to communicate with and set the frequencies of Maroochy Shire's repeater stations.
A Polish student used a modified TV remote controller to gain access to and control over the Lodz city tram system in Poland.45 The remote controller device allowed the student to interface with the tram’s network to modify track settings and override operator control. The adversary may have accomplished this by aligning the controller to the frequency and amplitude of IR control protocol signals.6 The controller then enabled initial access to the network, allowing the capture and replay of tram signals.4
- Communication Authenticity - Do not inherently rely on the authenticity provided by the network/link layer (e.g., 802.11, LTE, 802.15.4), as link layer equipment may have long lifespans and protocol vulnerabilities may not be easily patched. Provide defense-in-depth by implementing authenticity within the associated application-layer protocol, or through a network-layer VPN.7 Furthermore, ensure communication schemes provide strong replay protection, employing techniques such as timestamps or cryptographic nonces.
- Encrypt Network Traffic - Utilize strong cryptographic techniques and protocols to prevent eavesdropping on network communications.
- Software Process and Device Authentication - Ensure wireless networks require the authentication of all devices, and that all wireless devices also authenticate network infrastructure devices (i.e., mutual authentication). For defense-in-depth purposes, utilize VPNs or ensure that application-layer protocols also authenticate the system or device. Use protocols that provide strong authentication (e.g., IEEE 802.1X), and enforce basic protections, such as MAC filtering, when stronger cryptographic techniques are not available.
- Minimize Wireless Signal Propagation - Techniques can include (i) reducing transmission power on wireless signals, (ii) adjusting antenna gain to prevent extensions beyond organizational boundaries, and (iii) employing RF shielding techniques to block excessive signal propagation.8
- Alexander Bolshev, Gleb Cherbov. (2014, July 08). ICSCorsair: How I will PWN your ERP through 4-20 mA current loop. Retrieved January 5, 2020.
- Alexander Bolshev. (2014, March 11). S4x14: HART As An Attack Vector. Retrieved January 5, 2020.
- Marshall Abrams. (2008, July 23). Malicious Control System Cyber Security Attack Case Study– Maroochy Water Services, Australia. Retrieved March 27, 2018.
- John Bill. (2017, May 12). Hacked Cyber Security Railways. Retrieved October 17, 2019.
- Shelley Smith. (2008, February 12). Teen Hacker in Poland Plays Trains and Derails City Tram System. Retrieved October 17, 2019.
- Bruce Schneier. (2008, January 17). Hacking Polish Trams. Retrieved October 17, 2019.
- CISA. (2010, March 11). https://us-cert.cisa.gov/ncas/tips/ST05-003. Retrieved September 25, 2020.
- DHS National Urban Security Technology Laboratory. (2019, April). Radio Frequency Detection, Spectrum Analysis, and Direction Finding Equipment. Retrieved September 17, 2020.