macOS creates a fully read/write CDC-ACM serial device node with no TCC gate. Chained with a HID keyboard interface on the same USB composite device, this exfiltrates SSH keys, cloud credentials, and secrets in 24 seconds through a channel that shows no consent prompts. Apple was notified on 2026-04-26, declined the report on 2026-05-20, and I am publishing this today after 4 months of silence following my final response.

The first open source Mythic C2 agent with a full in-memory BOF loader for macOS and Linux, including Apple Silicon. No fork and runs, no baked in capabilities.

Pre-auth RCE in screensharingd — SRP frame-length validation returns success on oversized frames, bypassing authentication entirely. Root file read/write → code execution via crontab. No user interaction required.

Disclaimer

At WWDC 2025, Apple announced macOS 26 Tahoe. One of the new features in macOS Tahoe is a new disk image format: ASIF. Designed for use with virtual machines (its documentation lives under the Virtualization framework), ASIF takes a lot of inspiration from existing virtual disk formats. Practically, that means it’s another sparse virtual disk format, and functions very similar to sparse VMDK, VHDX or QCOW2 files (for the uninitiated, it allow you to store a large disk, or file, in a smaller, “sparse” manner).

Cisco Talos documents several macOS living-off-the-land (LOTL) techniques, demonstrating that native pathways for movement and execution remain accessible to those who understand the underlying architecture.