4-year campaign backdoored iPhones using possibly the most advanced exploit ever

Enlarge (credit: Tero Vesalainen)

Researchers on Wednesday presented intriguing new findings surrounding an attack that over four years backdoored dozens if not thousands of iPhones, many of which belonged to employees of Moscow-based security firm Kaspersky. Chief among the discoveries: the unknown attackers were able to achieve an unprecedented level of access by exploiting a vulnerability in an undocumented hardware feature that few if anyone outside of Apple and chip suppliers such as ARM Holdings knew of.

“The exploit’s sophistication and the feature’s obscurity suggest the attackers had advanced technical capabilities,” Kaspersky researcher Boris Larin wrote in an email. “Our analysis hasn’t revealed how they became aware of this feature, but we’re exploring all possibilities, including accidental disclosure in past firmware or source code releases. They may also have stumbled upon it through hardware reverse engineering.”

Four zero-days exploited for years

Other questions remain unanswered, wrote Larin, even after about 12 months of intensive investigation. Besides how the attackers learned of the hardware feature, the researchers still don’t know what, precisely, its purpose is. Also unknown is if the feature is a native part of the iPhone or enabled by a third-party hardware component such as ARM’s CoreSight