Keyless Car Theft Surges as Relay Attacks Undermine 85% of Models
Thieves can steal most modern keyless-entry vehicles in under a minute using inexpensive radio relay devices, bypassing alarms and leaving no trace of forced entry.
Modern vehicles equipped with keyless entry systems are facing a significant security threat, with a staggering 85% of models vulnerable to rapid theft via relay attacks. These attacks, which require minimal equipment and a pair of perpetrators, can result in a vehicle being stolen in less than a minute, leaving owners with no indication of forced entry or triggered alarms.
German auto club ADAC has conducted ongoing tests on keyless vehicle security, evaluating over 800 models. Their findings indicate that only about 15% of these vehicles are adequately protected against relay attacks. The remaining 85% can be compromised using readily available and inexpensive radio signal-extending equipment, according to ADAC's research.
This vulnerability is not confined to a single region; it spans the global automotive market. Law enforcement and insurance data reflect the growing impact of these thefts. In the Netherlands, vehicle crime bureau Stichting VbV reported that keyless entry systems were exploited in 59% of passenger cars stolen in 2025. Similarly, an analysis of US data from Mercury Insurance and the National Insurance Crime Bureau (NICB) in early 2026 linked the persistent high rates of vehicle theft in certain states to the exploitation of keyless entry systems, alongside other methods like OBD hacks.
The modus operandi typically involves two thieves working in tandem. One individual approaches the vehicle's owner or their residence, carrying a device that detects and amplifies the weak radio signal emitted by the key fob. This boosted signal is then relayed to a second device held by the accomplice positioned near the car. The car's system interprets this relayed signal as the legitimate key signal, unlocking the doors and allowing the thief to start the engine and drive away.
"What surprises us most is how easy it is to purchase systems that can copy keys or hardware for relay attacks," stated Clemens Muehlbacher, CEO of xAutomotive. He further noted that the increasing complexity of vehicle access methods, including online connections and NFC keys, expands the potential attack surface for cybercriminals. Beyond relay attacks, some thefts also involve gaining access to the vehicle's cabin to exploit the On-Board Diagnostics (OBD-II) port. Thieves can plug in programming tools to write a new key that the car will accept or clone existing key data.
Factory-installed alarms remain ineffective against these sophisticated attacks because they mimic the actions of a legitimate key. The car's internal computer registers the unlock and start commands as authorized user actions, thus keeping the alarm system dormant. While physical deterrents like steering wheel locks can slow down opportunistic thieves, they offer little resistance to electronic signal-based theft methods that operate within seconds and without audible alerts.
Carmakers are aware of these limitations, with some requiring owners to sign additional waivers for keyless-go options, acknowledging the inherent risks. To combat these threats, a layered defense strategy is recommended. This includes using signal-blocking pouches (Faraday pouches) for key fobs, storing keys away from exterior doors and windows, and installing OBD port locks. Advanced solutions like software immobilizers, which require a unique sequence entered via the car's controls to engage the transmission, or hidden kill switches that interrupt essential engine circuits, add further layers of security.
Vehicle owners can take several practical steps to mitigate their risk. Storing key fobs in signal-blocking pouches and keeping them away from external walls is crucial. Adding an OBD-II port lock provides a physical barrier against key programming. Implementing a software immobilizer or a kill switch introduces a necessary second authentication step. Furthermore, discreetly placing a GPS tracker can aid in vehicle recovery if a theft occurs. Parking in well-lit, monitored areas and utilizing visible deterrents can also discourage potential thieves.