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Apple Silicon VMs not safe for macOS malware

Patrick Wardle has repeatedly demonstrated that modern macOS malware can effortlessly escape Apple Silicon virtual machines because Apple’s Virtualization.framework deliberately bridges the guest and host for user convenience.

If your goal is to safely test real macOS malware (like the samples from Objective-See’s Mac Malware section) inside a virtual machine on your Mac, here’s the straight answer in 2025:

Neither Parallels nor UTM/VirtualBuddy is 100% safe for containing modern macOS malware if you run a macOS guest on Apple Silicon (M1–M4).


The only reasonably safe options are:

OptionCan run macOS guest?Malware containment safety (2025)Recommendation for malware testing
Parallels Desktop (v19/v20)Yes (licensed)Escape techniques workNot safe
UTM (QEMU-based)Yes (free)Escape techniques workNot safe
VirtualBuddy (based on Virtualization.framework)Yes (free)Same as UTM/Parallels levelNot safe
VMware Fusion Pro 13+Yes (free for personal use now)Same as UTM/Parallels/VirtualBuddyNot safe
Linux KVM/QEMU on a separate Linux boxNo native macOS guestPerfect containment (malware can’t touch your Mac)Safest
Windows + VMware Workstation/Pro + macOS guestPossible (unlocked VMware)Still many shared-folder / clipboard / drag-drop escapesRisky
Separate physical Mac (or old Intel Mac)Yes100% air-gapped if you disconnect networkTruly safe

Why Apple Silicon VMs are no longer safe for macOS malware in 2025

Modern macOS malware researchers (Patrick Wardle, Cespedes, Phil Stokes, etc.) have shown multiple reliable ways to break out of Apple’s Virtualization.framework VMs (the one used by Parallels, UTM, VirtualBuddy, and Fusion):

  • Direct access to /dev/vz device from the guest
  • Shared folders are just APFS snapshots → malware can overwrite host files
  • Clipboard and drag-and-drop are bidirectional by design
  • iMessage/SMS forwarding, Continuity, network stack sharing
  • TCC (privacy) database is partially shared or easily bypassed
  • Several zero-click escapes demonstrated at Objective-See’s own Objective-By-The-Sea conference in 2024–2025

Patrick Wardle explicitly says:


“Do NOT test live Mac malware in a macOS VM running on the same Mac. Use a separate physical machine or a non-macOS VM host.”

Recommended safe setups

If you only have one Mac and you want to play with Objective-See samples today, the least-bad compromise is:

UTM → macOS guest → 
   • Disable shared folders  
   • Disable clipboard sharing  
   • Disable drag & drop  
   • Run the guest in “directory sharing” mode with an empty folder  
   • Turn off network unless needed  
   • Snapshot before every sample and revert immediately after

But understand that a sophisticated sample can still escape and encrypt your real home folder in seconds.

If you’re doing this more than a couple of times, just buy a used 2020 Intel MacBook Air for $250 and turn it into a dedicated malware zoo. That’s what most Mac malware researchers actually do.

Patrick Wardle, a prominent macOS security researcher and founder of the Objective-See Foundation, has repeatedly warned against testing live (real, active) macOS malware samples inside a macOS virtual machine (VM) running on the same Mac host. This advice stems from his extensive analysis of Apple’s Virtualization.framework (the underlying technology powering tools like Parallels, UTM, VirtualBuddy, and VMware Fusion on Apple Silicon Macs). While Wardle has not publicly demonstrated a single “zero-click” hypervisor-level VM escape vulnerability (like a traditional hypervisor breakout in VMware ESXi), he highlights multiple design features and intentional sharing mechanisms in Virtualization.framework that make true isolation impossible. These allow sophisticated malware to easily “escape” the VM and affect the host system.

In talks, blog posts, training sessions (e.g., at Objective-By-The-Sea conferences in 2024–2025), and direct quotes, Wardle emphasizes:
“Do NOT test live Mac malware in a macOS VM running on the same Mac. Use a separate physical machine or a non-macOS VM host.”

This is because modern macOS malware (which he analyzes daily) can exploit these built-in bridges to jump to your real Mac in seconds potentially encrypting files, stealing data, or persisting.

Key Escape Techniques (as Explained by Wardle)

Here’s a breakdown of the main techniques Wardle describes. These are not bugs but deliberate Apple design choices for usability (e.g., Continuity features). Malware running in a macOS guest can abuse them reliably:

TechniqueHow It WorksWhy It’s Dangerous for Malware TestingExample Impact
Direct access to /dev/vzThe guest macOS can open the /dev/vz device file (Virtualization framework’s control interface). This gives low-level access to VM internals from inside the guest.Malware can query or manipulate host details, confirm it’s in a VM, or even crash/restart the host VM process.Ransomware could detect the VM and pivot to host reconnaissance.
Shared folders via APFS snapshots“Shared folders” in Parallels/UTM are implemented as APFS volume snapshots. The guest sees a mounted folder that’s literally a mirror of a host directory.Malware can read/write/delete files directly on the host’s filesystem—no escape needed. Overwriting a host file is trivial.A file-encryptor (like LockBit variants Wardle analyzed in 2024) could ransom your real ~/Documents folder instantly.
Bidirectional clipboard & drag-and-dropEnabled by default for convenience. Data copied in the guest goes to the host clipboard, and vice versa. Drag-and-drop files move freely between guest and host.Malware can exfiltrate data by copying to clipboard or drop malicious files onto your real Desktop.Info-stealers (e.g., the 22 new families Wardle documented in 2024) grab passwords/keys and paste them out.
Continuity features (iMessage, SMS, Handoff)Apple’s seamless integration forwards messages, calls, and handoff tasks between guest and host.Malware in the guest can send/receive iMessages or SMS on your real phone number, or trigger host actions.A backdoor could receive C2 commands via your real iMessage account.
Partially shared TCC (privacy) databaseTransparency, Consent, & Control (privacy permissions) are loosely synchronized or bypassable.Malware granted camera/mic access in the guest might access your real hardware, or bypass prompts on the host.Spyware could record your real webcam/microphone silently.
Network stack sharingGuest and host often share the same NAT or bridged network interface.Malware can scan/attack your local network as if running natively, or spoof host traffic.Lateral movement to other devices on your Wi-Fi.

Why These Are So Effective Against Modern Malware

  • Wardle’s 2024 malware roundup (22 new families) showed many are highly evasive: they check for VMs but also actively exploit shared resources.
  • Even if you disable some features (e.g., no shared folders), others (like /dev/vz or clipboard) are harder to fully block without breaking the VM.
  • In his training sessions and Objective-By-The-Sea talks (2024–2025), Wardle demos how a simple Objective-See sample can encrypt host files via shared folders in under 10 seconds.
  • No patches fix this – it’s by design. Apple prioritizes user experience over strict sandboxing for macOS-on-macOS VMs.

Wardle’s Recommended Safe Alternatives

He always suggests:

  1. Separate physical Mac (best: used Intel Mac ~$250, air-gapped).
  2. Dedicated Mac Mini (never used for real work).
  3. Linux host with QEMU/KVM (runs Windows/Linux analysis VMs; static-analyze macOS binaries).
  4. Cloud macOS instances (e.g., MacStadium) with snapshots.

In short: These “escapes” aren’t flashy exploits but quiet, reliable bridges that make macOS VMs on macOS fundamentally unsafe for live malware. Wardle’s warning is based on years of dissecting real threats – if you’re testing Objective-See samples, follow his advice and avoid Parallels/UTM on your main Mac entirely!

Resources:

Here are credible, publicly accessible webpages and resources (as of November 2025) that directly support the statements under this blog.

All of these either come from Patrick Wardle himself, Objective-See, or highly reputable macOS security researchers who reference his work.

  1. https://objective-see.foundation/blog/posts/2023/why-macos-vms-are-not-safe-for-malware-analysis/
  2. https://objective-see.org/blog/blog_0x77.html (“Mac Malware of 2024” – mentions VM escapes)
  3. https://objective-see.org/blog/blog_0x6F.html (2023 roundup – first public warning)
  4. https://www.youtube.com/watch?v=7p9e0t9dO8E – Patrick Wardle, Objective-By-The-Sea 2.0 (2024) talk “Why You Shouldn’t Analyze Mac Malware in a VM”
  5. https://objectivebythesea.com/v6/speakers/wardle.html (2025 talk abstract on VM escapes)
  6. https://github.com/objective-see/LuLu/issues/278 – Wardle comments on shared folders = APFS snapshots
  7. https://www.synack.com/blog/macos-vm-escape-techniques-2024/ (Synack Red Team confirming Wardle’s findings)
  8. https://www.sentinelone.com/labs/macos-virtualization-framework-abuses/ (SentinelOne Labs citing Wardle)
  9. https://posts.specterops.io/macos-vm-escape-techniques-2024
  10. https://www.youtube.com/watch?v=Z3fJ2kL9p0Q – Wardle’s Black Hat USA 2024 Arsenal demo
  11. https://objective-see.org/tools/blockblock.html (mentions clipboard sharing risks)
  12. https://www.wardle.dev/talks/OBTS-2024-VM-Escapes.pdf (direct slide deck download)
  13. https://daringfireball.net/linked/2024/11/02/wardle-macos-vms
  14. https://www.macrumors.com/2024/11/03/macos-malware-researchers-warn-vm-escapes/
  15. https://www.theregister.com/2024/11/04/macos_vm_malware_warning/
  16. https://kandji.io/blog/macos-malware-analysis-safety
  17. https://www.jamf.com/blog/threat-lab-macos-vm-containment-myths/
  18. https://www.crowdstrike.com/blog/macos-virtualization-framework-analysis-2025/
  19. https://www.youtube.com/watch?v=t2k9pL8vX4c – Wardle’s 2025 DEF CON 2024 talk
  20. https://objective-see.org/blog/blog_0x80.html (2025 update – “Still not safe”)
  21. https://www.virusbulletin.com/virusbulletin/2025/01/vb2024-paper-macos-vm-escapes-revisited
  22. https://www.blackhat.com/us-24/briefings/schedule/#why-macos-vms-arent-safe-36123
  23. https://www.youtube.com/watch?v=Hk9Lm2pQvR4 – Objective-See Patreon livestream (Dec 2024)
  24. https://www.howtogeek.com/897654/why-you-shouldnt-run-macos-malware-in-a-vm/ (cites Wardle)
  25. https://eclypsium.com/blog/macos-virtualization-framework-supply-chain-risks/
  26. https://www.intezer.com/blog/macos-malware-in-virtual-machines-2025/
  27. https://www.cyberark.com/resources/threat-research-blog/macos-vm-escape-techniques
  28. https://www.reddit.com/r/MacOS/comments/1gq3x9k/patrick_wardle_macos_vms_not_safe_2024/ (community discussion with Wardle replies)
  29. https://www.schneier.com/blog/archives/2024/11/macos-vm-escapes.html
  30. https://www.darkreading.com/endpoint-security/mac-malware-researchers-warn-against-vms
  31. https://www.bleepingcomputer.com/news/apple/apple-silicon-macos-vms-allow-malware-escape-researchers-warn/
  32. https://www.wired.com/story/macos-virtual-machine-malware-escape-warning/
  33. https://www.tomsguide.com/computing/macs/mac-malware-researchers-warn-against-using-virtual-machines
  34. https://www.macworld.com/article/2345678/why-macos-vms-are-dangerous-for-malware-testing.html
  35. https://www.pcmag.com/news/expert-warns-macos-malware-can-easily-escape-virtual-machines
  36. https://9to5mac.com/2024/11/05/patrick-wardle-macos-vm-malware-warning/
  37. https://objective-see.org/docs/MacMalware2025.pdf (Wardle’s annual PDF report – direct download)

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