Yes. But what if the world was 1/3rd Linux, 1/3rd windows, 1/3rd OSX?
The 1/3 running macOS (they haven’t called in OS X in many years now) wouldn’t have to worry, because Apple provides kernel event access for security tools running in user space. The CrowdStrike Falcon Sensor driver on macOS runs as a System Extension, and runs 100% in user space (“Ring 3” in Intel parlance) only — so if it misbehaves, the kernel can just shut it down and continue on its merry way.
The problem with Windows (and to a certain extend Linux) is that Falcon Sensor needs to run in kernel mode (Ring 0) on those OS’s, and if it fucks up you lose all guarantees that the kernel and all of the apps running on the system haven’t been fucked with, hence the need for a full system crash/shutdown. The driver can (and did) put these systems in an indeterministic state. But that can’t happen on modern macOS with modern System Extensions.
You don’t have to run in Ring 0 to detect events occurring in Ring 0.
Besides which, as kexts are being obsoleted by Apple getting code to run inside Ring 0 in macOS that isn’t from Apple itself is going to be extremely difficult.
The 1/3 running macOS (they haven’t called in OS X in many years now) wouldn’t have to worry, because Apple provides kernel event access for security tools running in user space. The CrowdStrike Falcon Sensor driver on macOS runs as a System Extension, and runs 100% in user space (“Ring 3” in Intel parlance) only — so if it misbehaves, the kernel can just shut it down and continue on its merry way.
The problem with Windows (and to a certain extend Linux) is that Falcon Sensor needs to run in kernel mode (Ring 0) on those OS’s, and if it fucks up you lose all guarantees that the kernel and all of the apps running on the system haven’t been fucked with, hence the need for a full system crash/shutdown. The driver can (and did) put these systems in an indeterministic state. But that can’t happen on modern macOS with modern System Extensions.
I see. How effective is a security tool that can’t stop malicious software that makes itself in ring 0?
You don’t have to run in Ring 0 to detect events occurring in Ring 0.
Besides which, as kexts are being obsoleted by Apple getting code to run inside Ring 0 in macOS that isn’t from Apple itself is going to be extremely difficult.
Right, but part of the appeal of tools like crowd strike and sentinelone is that they can stop them when they’re in ring 0. And rollback changes. Etc.