can thieves use universal car fobs to break into cars

[McErin]

Yes, thieves can use devices that function as universal car fobs, but their effectiveness is highly dependent on the specific car's security technology. Modern vehicles with robust keyless entry systems are significantly more resistant to these attacks than older models. The primary method used is a relay attack, where thieves exploit the convenience of keyless entry by amplifying the signal from your actual key fob, which might be inside your house, to unlock and start the car parked outside. Universal fobs that simply try random codes are largely ineffective against modern rolling code systems.

The vulnerability lies more in the method of attack than the tool itself. Here’s a breakdown of common car security systems and their susceptibility:

Security System Type	Susceptibility to Relay Attacks	Common Vehicle Examples (Model Years)
Traditional Key & Lock	Low (requires physical manipulation)	Older models (pre-2000)
Basic Remote Key Fob (Fixed Code)	High (signal can be intercepted and replayed)	Early 2000s models
Rolling Code Key Fob	Low for code grabbing, but vulnerable to jamming attacks	Most vehicles from mid-2000s onward
Proximity Keyless Entry & Start (PKES)	High to relay attacks if not properly shielded	Many modern luxury and mainstream cars (2015-Present)
Ultra-Wideband (UWB) & Bluetooth PKES	Very Low (uses secure, short-range distance measurement)	Latest models from brands like BMW, Tesla, Mercedes-Benz (2021-Present)

To protect your vehicle, the most effective step is to store your key fob in a Faraday bag or pouch when at home. This metallic-lined container blocks all radio signals, preventing thieves from amplifying them. Alternatively, keep your fobs away from doors and windows. For cars with keyless start, also consider using a steering wheel lock; it's a visible, physical deterrent that makes the vehicle a less attractive target regardless of electronic vulnerabilities.

[Asher]

Honestly, it’s a real concern. My neighbor had his SUV stolen right from his driveway last winter. The police said it was likely a relay attack—they used a device to pick up the signal from his key fob that was on a hook by the front door. Now, I keep my keys in a little metal box I bought online. It’s a cheap fix that gives me way more peace of mind. It’s not about having a fancy car; it’s about not making it easy for them.

[SanLily]

From a technical standpoint, the term "universal fob" is misleading. Thieves use specialized transceivers to execute relay attacks. The system's weakness is that the car continuously searches for its fob's signal. These devices simply extend that signal's range. The solution is cryptographic. Newer systems like Ultra-Wideband (UWB) measure the precise time it takes for a signal to travel, making relay attacks physically impossible by detecting the signal delay introduced by the attacker's equipment.

[JackDella]

We see these cases often. The thieves work in pairs, one standing by the car with a device and another near the house with a receiver. They aren’t hacking anything; they’re just tricking the car into thinking the key is nearby. We recommend simple, physical barriers. A steering wheel lock is incredibly effective because it turns a quick, electronic crime into a slow, noisy, physical one. That’s often enough to make them move on to an easier target. Always report suspicious activity.

[SamanthaRose]

Think of it like your home Wi-Fi password. An old, simple password is easy to guess. A modern, constantly changing password is very hard to crack. Most new cars have the equivalent of a changing password. The real risk is if you leave your "password" (the key fob) right by the front door. So, just move your keys deeper into your house or use a signal-blocking pouch. It’s a simple habit that dramatically increases your car’s security against this specific type of digital break-in.