Invisible Calendar Invites Used to Hack iPhones and Install QuaDream Spyware

The spyware was found to be particularly advanced, using techniques such as sandbox evasion and persistence to remain undetected on the compromised device.

According to the report, QuaDream’s spyware has been linked to a group known as Candiru, which is also based in Israel and has been accused of selling spyware to various governments around the world.

Microsoft has stated that it has taken steps to protect its customers from QuaDream, but warns that these types of attacks will continue to occur as long as spyware companies are allowed to operate without oversight.

Attackers were able to compromise iPhones by using backdated and “invisible” iCloud calendar invitations, according to reports.

The attackers used this technique to exploit the ENDOFDAYS vulnerability, which runs automatically once an iCloud calendar invitation is added to the user’s calendar without notification or prompt. This allowed the attacks to remain undetected by the targets, making it an effective technique for compromising devices.

Citizen Lab researchers have reported that “at least five civil society victims of QuaDream’s spyware and exploits” were found in various regions, including Central Asia, Southeast Asia, Europe, North America and the Middle East. The victims reportedly include journalists, political opposition figures, and an NGO worker, but no names were provided.

The malware used in the campaign, dubbed KingsPawn by Microsoft, was designed to self-delete and clean out any traces from victims’ iPhones to evade detection, according to the report. Additionally, Citizen Lab discovered a process name used by the spyware through their analysis of the self-destruct feature.

The capabilities of QuaDream’s spyware, discovered during analysis, include recording audio from phone calls and the microphone, taking pictures with the device’s camera, exfiltrating items from the device’s keychain, generating iCloud time-based one-time password login codes for future dates, running SQL queries, tracking the device’s location, and performing various filesystem operations. The spyware also has the ability to clean remnants left behind by zero-click exploits.

QuaDream servers were discovered by Citizen Lab in several countries, including Bulgaria, the Hungary, Israel, Mexico, Czech Republic, Romania, Ghana, Uzbekistan, Singapore, the United Arab Emirates (UAE), and Mexico.