The flaw affected all Apple’s operating systems, the researchers said.
The researchers at the University of Toronto’s Citizen Lab said the flaw allowed spyware from the world’s most infamous hacker-for-hire firm, NSO Group, to directly infect the iPhone of a Saudi activist.
It was the first time a so-called “zero-click” exploit had been caught and analyzed, said the researchers, who found the malicious code on Tuesday and immediately alerted Apple. They said they had high confidence the Israeli company NSO Group was behind the attack, adding that the targeted activist asked to remain anonymous.
Toronto-based Citizen Lab first identified the security flaw earlier this month and flagged it to Apple. (Anand Ram/CBC) ‘Maliciously crafted’
“We’re not necessarily attributing this attack to the Saudi government,” said researcher Bill Marczak.
Although Citizen Lab previously found evidence of zero-click exploits being used to hack into the phones of al-Jazeera journalists and other targets, “this is the first one where the exploit has been captured so we can find out how it works,” said Marczak.
Security experts say that average iPhone, iPad and Mac users generally don’t need to worry because such attacks are highly targeted, however, the discovery still alarmed security professionals.
Malicious image files were transmitted to the activist’s phone via the iMessage instant-messaging app before it was hacked with NSO’s Pegasus spyware, which opens a phone to eavesdropping and remote data theft, Marczak said.
It was discovered during a second examination of the phone, which forensics showed had been infected in March. He said the malicious file causes devices to crash. NSO Group did not immediately respond to an email seeking comment.
In a blog post, Apple said it was issuing a security update for iPhones and iPads because a “maliciously crafted” PDF file could lead to them being hacked. It said it was aware that the issue may have been exploited and cited Citizen Lab. In a subsequent statement, Apple security chief Ivan Krstic commended Citizen Lab and said such exploits “are not a threat to the overwhelming majority of our users.” He noted, as he has in the past, that such exploits typically cost millions of dollars to develop and often have a short shelf life. Apple didn’t respond to questions regarding whether this was the first time it had patched a zero-click vulnerability.
Users should get alerts on their iPhones prompting them to update the phone’s iOS software. Those who want to jump the gun can visit phone settings, click “General” then “Software Update,” and trigger the patch update directly. Citizen Lab called the iMessage exploit FORCEDENTRY and said it was effective against Apple iOS, MacOS and WatchOS devices.
Messaging apps easy targets Researcher John Scott-Railton said the news highlights the importance of securing popular messaging apps against such attacks.
“Chat apps are increasingly becoming a major way that nation-states and mercenary hackers are gaining access to phones,” he said. “And it’s why it’s so important that companies focus on making sure that they are as locked down as possible.” The researchers said it also exposes — again — that NSO’s business model involves selling spyware to governments that will abuse it, not just to law enforcement officials chasing cyber criminals and terrorists, as NSO claims.