Researchers Devise iPhone Malware That Runs Even When Device Is Turned Off

An anonymous reader quotes a report from Ars Technica: When you turn off an iPhone, it doesn't fully power down. Chips inside the device continue to run in a low-power mode that makes it possible to locate lost or stolen devices using the Find My feature or use credit cards and car keys after the battery dies. Now researchers have devised a way to abuse this always-on mechanism to run malware that remains active even when an iPhone appears to be powered down. It turns out that the iPhone's Bluetooth chip -- which is key to making features like Find My work -- has no mechanism for digitally signing or even encrypting the firmware it runs. Academics at Germany's Technical University of Darmstadt figured out how to exploit this lack of hardening to run malicious firmware that allows the attacker to track the phone's location or run new features when the device is turned off. This video provides a high overview of some of the ways an attack can work.

The findings (PDF) have limited real-world value since infections required a jailbroken iPhone, which in itself is a difficult task, particularly in an adversarial setting. Still, targeting the always-on feature in iOS could prove handy in post-exploit scenarios by malware such as Pegasus, the sophisticated smartphone exploit tool from Israel-based NSO Group, which governments worldwide routinely employ to spy on adversaries. Besides allowing malware to run while the iPhone is turned off, exploits targeting LPM could also allow malware to operate with much more stealth since LPM allows firmware to conserve battery power. And of course, firmware infections are already extremely difficult to detect since it requires significant expertise and expensive equipment.