Your Phone Won’t Be the Next Exploding Pager

For two days this week, Hezbollah has been rocked by a series of small explosions across Lebanon, injuring thousands and killing at least 25. But these attacks haven’t come from rockets or drones. Instead, they’ve resulted from boobytrapped electronics—including pagers, walkie-talkies, and even, reportedly, solar equipment—detonating in coordinated waves. As details come into view of the elaborate supply chain attack that compromised these devices, citizens on the ground in Lebanon and people around the world are questioning whether such attacks could target any device in your pocket.

The campaign to compromise key Hezbollah communication infrastructure with explosives was clearly elaborate and involved. The operation, which is widely believed to have been perpetrated by Israel, goes far beyond past examples of hardware supply chain attacks and may be a source of inspiration for future spycraft around the world. But sources tell WIRED that the specific scale and scope of the effort would not be easily replicated in other contexts. And, more broadly, the resources and precision involved in carrying out such an attack would be prohibitively difficult to maintain over time for key consumer devices like smartphones—which are used so widely and regularly scrutinized by researchers, product testers, and repair technicians.

“I do think there is absolutely potential to see more of this in the longer term, not targeting civilians, but generally targeting other military actors,” says Zachary Kallenborn, an adjunct nonresident fellow with the Center for Strategic and International Studies. Kallenborn says militaries are increasingly relying on commercial technology—from drones to communications devices—all of which could be compromised if supply chains can be exploited by adversaries. “These systems are being sourced from all over the globe,” he says. “What that means, then, is that you also have these global supply chains supporting them.”

While full details of the attacks are still coming to light, the devices that detonated were seemingly compromised with explosives before they arrived in Hezbollah members’ hands. Alan Woodward, a cybersecurity professor at the University of Surrey, says he suspects that an attacker would plant explosives in a device during the manufacturing process, rather than intercepting gadgets after they are finished and then taking them apart to plant explosives. Reporting by the New York Times on Wednesday evening seemed to confirm this theory, indicating that Israel directly manufactured the compromised devices via shell companies. Israel has not commented on any of the attacks.

Early theories that cyberattacks caused device batteries to overheat and explode have been ruled out by cybersecurity experts. The force of the blasts seen in on-the-ground footage would not be consistent with battery fires or explosions, especially given the small size of pager and walkie-talkie batteries.

Lebanon’s political landscape and ongoing economic crisis, coupled with regional fighting between Hezbollah and Israel, created specific opportunities for sabotage. Hezbollah is isolated globally, with countries like the United States and United Kingdom classifying it as a terrorist organization while other countries, such as Russia and China, maintain relations. This impacts Hezbollah’s avenues for importing equipment and vetting suppliers.

Amid ongoing violent conflict with Israel, Hezbollah’s digital communications and activities are also under constant barrage from Israeli hackers. In fact, this constant digital assault reportedly played a role in pushing Hezbollah away from smartphone communication and toward pagers and walkie-talkies in the first place. “Your phone is their agent,” Hezbollah leader Hassan Nasrallah said in February, referring to Israel.

The commercial spyware industry has shown it is possible to fully compromise target smartphones by exploiting chains of vulnerabilities in their mobile operating systems. Developing spyware and repeatedly finding new operating system vulnerabilities as older ones are patched is a resource-intensive process, but it is still less complicated and risky than conducting a hardware supply chain attack to physically compromise devices during or shortly after manufacturing. And for an attacker, monitoring a target’s entire digital life on a smartphone or laptop is likely more valuable than the device’s potential as a bomb.

“I’d hazard a guess that the only reason we aren’t hearing about exploding laptops is that they’re collecting too much intelligence from those,” says Jake Williams, vice president of research and development at Hunter Strategy, who formerly worked for the US National Security Agency. “I think there’s also potentially an element of targeting, too. The pagers and personal radios could pretty reliably be expected to stay in the hands of Hezbollah operatives, but more general purpose electronics like laptops could not.”

There are other more practical reasons, too, that the attacks in Lebanon are unlikely to portend a global wave of exploding consumer electronics anytime soon. Unlike portable devices that were originally designed in the 20th century, the current generation of laptops and particularly smartphones are densely packed with hardware components to offer the most features and the longest battery life in the most efficient package possible.

University of Surrey’s Woodward, who regularly takes apart consumer devices, points out that within modern smartphones there is very limited space to insert anything extra, and the manufacturing process can involve robots precisely placing components on top of each other. X-rays show how tightly packed modern phones are.

“When you open up a smartphone, I think the only way to get any sort of meaningful amount of high explosive in there would be to do something like replace one of the components,” he says, such as modifying a battery to be half battery, half explosives. But “replacing a component in a smartphone would compromise its functionality,” he says, which could lead a user to investigate the malfunction.

In contrast, the model of pager linked to the explosions—a “rugged” device with 85 days of battery life—included multiple replaceable parts. Ang Cui, founder of the embedded device security firm Red Balloon Security, examined the schematics of the pager model apparently used in the attacks and told WIRED that there would be free space inside to plant explosives. The walkie-talkies that exploded, according to the manufacturer, were discontinued a decade ago. Woodward says that when opening up redesigned, current versions of older technologies, such as pagers, many internal electronic components have been “compressed” down as manufacturing methods and processor efficiency have improved.

Smartphone production lines also operate under stricter security measures, especially for high-cost devices like Apple’s iPhones and Google’s flagship Pixel phones. This is partly to guarantee production quality, but also to ensure that employees don’t leak trade secrets or prototypes. Not all low-end Android phones are manufactured with such intense oversight, but it would be more difficult to secretly take over manufacturing of a smartphone than a forgotten pager model. In countries like China, where many devices are manufactured, there is always the possibility of a domestic operation to plant backdoors, but such a scheme would need to be elaborate to skirt international scrutiny of the devices

To find exploding cell phones, you have to go back to 20th century tech. In 1996, Palestinian bombmaker Yahya Ayyash was killed when his mobile phone exploded as he answered a call. His old-style phone—which the New York Times said was ”reportedly a small, slim model that fits in a pocket”—had 50 grams of explosives planted inside it, likely by Israel’s security services. The explosion was reportedly triggered by a radio signal emitted from a plane flying above. And unlike the pager and walkie-talkie attacks this week, Ayyash’s phone was part of a highly targeted attack on him alone.

Even if this week’s exploding device campaign doesn’t have immediate implications for every smartphone in every pocket, though, it expands enormously the specter of hardware supply chain attacks.

“I think that every shady organization worldwide will now be checking their new devices—especially those ordered in bulk from the manufacturer—for explosives,” says a longtime hardware hacker and tech procurement specialist who asked to be identified as Null Pointer. “This hit so hard because it was novel and no one in that community knew to look for it. It’s ingenious.”