Citizen Lab's digital threat researchers have discovered a new zero-click iMessage exploit that was exploited to install NSO Group's Pegasus spyware on Bahraini activists' smartphones. In total, nine Bahraini activists (including members of the Bahrain Center for Human Rights, Waad, and Al Wefaq) had their iPhones hacked in a campaign conducted by a Pegasus operator linked to the Bahraini government with high confidence, according to Citizen Lab. 

After being compromised using two zero-click iMessage exploits (that do not involve user participation), the spyware was installed on their devices: the 2020 KISMET exploit and a new never-before-seen exploit named FORCEDENTRY. 

In February 2021, Citizen Lab first noticed NSO Group deploying the new zero-click FORCEDENTRY iMessage attack, which bypasses Apple's BlastDoor protection. BlastDoor, a structural change in iOS 14 aimed to stop message-based, zero-click attacks like this, had just been released the month before. BlastDoor was designed to prevent Pegasus attacks by operating as a "tightly sandboxed" service responsible for "almost all" of the parsing of untrusted data in iMessages, according to Samuel Groß of Google Project Zero.

“We saw the FORCEDENTRY exploit successfully deployed against iOS versions 14.4 and 14.6 as a zero-day,” Citizen Lab said. “With the consent of targets, we shared these crash logs and some additional phone logs relating to KISMET and FORCEDENTRY with Apple, Inc., which confirmed they were investigating.” 

Attacks like the ones revealed by Citizen Lab, according to Ivan Krstić, head of Apple Security Engineering and Architecture, are highly targeted and hence nothing to worry about for most people, at least. Such attacks are "very complex, cost millions of dollars to design, often have a short shelf life, and are used to target specific individuals," according to Krstić. 

In addition to Apple's iMessage, NSO Group has a history of using other messaging apps, such as WhatsApp, to spread malware. Nonetheless, Citizen Lab believes that disabling iMessage and FaceTime in this circumstance, with these specific threats, may have blocked the threat actors. Researchers emphasized that disabling iMessage and FaceTime would not provide total security from zero-click assaults or adware.

NSO Group stated in a statement to Bloomberg that it hasn't read the report yet, but it has concerns about Citizen Lab's techniques and motivations. According to the company's statement, "If NSO gets reliable evidence relating to the system's misuse, the company will thoroughly investigate the claims and act accordingly."