Macintosh secondary operating systems and security concerns

Under some scenarios, it is possible to cause corruption on macOS side, by overwriting file system information. If you are concerned, look at BitLocker for Windows and encryption for Linux. macOS FileVault can also help.

There is no substitute for a good backups.

kjkkkk wrote:

what about The “MacOS Base System” modifications and infections? Can it be done?

If you are referring to images provided by Apple's Internet Recovery system, this is verified by the Apple servers.

• what about “Firmware” infections? What are the things that macOS pro users need to be familiar with, with regard to the Firmware infections, also the relationship of firmware infections and secondary operating systems?

See What is a firmware password on Mac? - Apple Support as reference. Apple's EFI updates use signature verification using PKI.

• Some versions of Linux can be installed on external hard drives. While using that Linux, say a security exposure happens and a cyber offender gets the root access of the Linux system. Can he access the “macOS base system”, cause “firmware infections” and make things in a way that the Mac device can not be completely clean by restoring to factory settings?

This is a possible use-case. See What is the Startup Security Utility on Mac? - Apple Support for reference. We are now veering away from software security models to physical security of devices.

There are concerns about NSA having technologies which cause the device to stay infected all its lifetime, and hard drive formats wont fix it. Would you clarify the matter please?

You can create EFI malware. EFI layer also has signature validation. Apple now bundles EFI within macOS updates which has signature validation using certificates. As an example, Apple T2 prevents Linux being installed as bootable system. The user needs to intentionally disable safeguards to allow this. VM engines can also have security issues. If you are concerned about such level of compromises, Apple Genii can also do a 'hardware' wipe.

Wine has performance penalties. I have played with Wine (not CrossOver).

You can also use VM engines, which run as a GuestOS on the underlying HostOS (macOS on Macs). Some of the security features of macOS then come into play. https://developer.apple.com/documentation/security is primarily directed at developers, but does provide some insight.

With the release of macOS Big Sur (directed towards ARM), the Rosetta2 layer (based on the original OS9 to OSX Rosetta philosophy) will also provide some capabilities.

You are correct, very few commercial organizations have any interest in 'legacy', because it conflicts with growth of revenue streams that shareholders much desire. Planned obsolescence is a wonderful tool for growing revenue streams.

There are others on ASC who are better experts in the Software/Hardware Security than I am. I will ask them to chime in as well.

The partition that contains macOS is 'visible' through Windows disk utilities and can be manipulated causing corruption and/or data loss. Ransomware can use such back doors to cause problems.