How might Israel have triggered Hezbollah pager explosions?

Pagers used for communication between Hezbollah fighters reportedly exploded this afternoon, injuring hundreds, according to Lebanese security services.

Speculation has since mounted that the technology was somehow hacked or sabotaged by Israeli intelligence.

One source close to Hezbollah claimed that the incident came as a direct result of an ‘Israeli breach’ of its communications, though this has not been confirmed and Israel has not yet commented.

A different official said on condition of anonymity that the cause of the explosions was likely the lithium batteries that power the pagers.

While lithium-ion batteries are commonly used in consumer electronics, they can overheat and catch on fire – even exploding violently in some cases. 

The remnants of what is believed to be a pager carried by a Lebanese militant that detonated earlier today

Pagers used by Hezbollah members for vital communications exploded this afternoon, injuring hundreds

This is due to a phenomenon called thermal runaway, a chemical chain reaction which occurs when the battery experiences a rapid temperature change.

As this chemical reaction progresses it can lead to a sudden release of energy which can cause devices to explode with intense force and heat.

Thermal runaway is triggered when the battery is overheated, punctured or overcharged.

There is yet to be any official confirmation on what caused the pagers to detonate simultaneously, however, Lebanese military sources have suggested that the devices were detonated as part of an Israeli attack.

It is possible that Israeli forces or some other actor could have hacked these devices and remotely overcharged the battery, triggering a thermal runaway.

Pagers often use unencrypted communications channels and outdated software, making them extremely easy targets for an attack.

One-way pagers are passive receivers and so cannot be tracked, but when a message is sent it activates every pager transmitter in the area.

By hijacking the broadcast signal, an adversary could have conceivably infected every single pager on the network simultaneously. 

Police officers inspect a car inside of which a hand-held pager exploded, Beirut, Lebanon, Tuesday, Sept. 17, 2024

A virus could have been implanted into the Hezbollah pager network and allowed to remain dormant on the devices until it had spread widely.

This malware may have been remotely triggered or activated on a pre-programmed timer.

Video shows that the devices appeared to receive a message moments before the devices detonated.

This signal could have been the trigger for the explosion or it may have been used to ensure that the fighters were holding the devices when they exploded.

If these explosions are the product of a cyberattack then this is an exceptionally rare case of cyberwarfare causing disruption to physical infrastructure.

Earlier this year, Hezbollah’s leader Hassan Nasrallah urged members of his organisation to revert to using the pagers for vital communications, reasoning that modern smartphones would be more susceptible to cyber attacks by Israeli forces. 

But just like mobile phones and many other consumer electronics, pagers also rely on rechargeable lithium batteries to function.

The battery fires can burn up to 590 degrees celsius (1,100 F) when ignited.