Key IOCs for Pegasus and Predator Spyware Removed with iOS 26 Update

Summary

As iOS 26 is being rolled out, our team noticed a particular change in how the operating system handles the shutdown.log file: it effectively erases crucial evidence of Pegasus and Predator spyware infections. This development poses a serious challenge for forensic investigators and individuals seeking to determine if their devices have been compromised at a time when spyware attacks are becoming more common.The Power of the shutdown.logFor years, the shutdown.log file has been an invaluable, yet often overlooked, artifact in the detection of iOS malware. Located within the Sysdiagnoses in the Unified Logs section (specifically, Sysdiagnose Folder -> system_logs.logarchive -> Extra -> shutdown.log), it has served as a silent witness to the activities occurring on an iOS device, even during its shutdown sequence.In 2021, the publicly known version of Pegasus spyware was found to leave discernible traces within this shutdown.log. These traces provided a critical indicator of compromise, allowing security researchers to identify infected devices. However, the developers behind Pegasus, NSO Group, are constantly refining their techniques, and by 2022 Pegasus had evolved.Pegasus's Evolving Evasion TacticsWhile still leaving evidence in the shutdown.log, their methods became more sophisticated. Instead of leaving obvious entries, they began to completely wipe the shutdown.log file. Yet, even with this attempted erasure, their own processes still left behind subtle traces. This meant that even a seemingly clean shutdown.log that began with evidence of a Pegasus sample was, in itself, an indicator of compromise. Multiple cases of this behavior were observed until the end of 2022, highlighting the continuous adaptation of these malicious actors.Following this period, it is believed that Pegasus developers implemented even more robust wiping mechanisms, likely monitoring device shutdown to ensure a thorough eradication of their presence from the shutdown.log. Researchers have...