Localhost MALWARE will sandbox you inside

Everything that you describe is possible using a Windows VM whether on a Mac or Windows. On the Mac the only thing that is affected is the Windows partition and you are subject to the same Malware as seen on other Windows systems, but it has no affect on MacOS. The iPhone 17 is not affected at all by any VM installed on a computer and no virus is being propagated from a Windows install to an iPhone.

My recommendation is to properly remove VirtualBox. The instructions are provided here along with the Installation instructions.

https://www.virtualbox.org/manual/topics/installation.html#install-mac-uninstall

localhost and all of 127/8 go nowhere but to “self”. This address block doesn’t “mask” anything, it’s just a well-established part of IP networking intended to provide a path to “self”.

If public IP addresses (not a private block, not localhost) are to be obfuscated, Apple iCloud+ Private Relay, Tor, I2P, and similar mechanisms can potentially be options here depending on specific local requirements.

With all that’s installed here and presumably including a selection of add-on security hardware and software and guests, some routing oddities are to be expected pending troubleshooting.

For assistance with running and securing Microsoft Windows guests on VirtualBox, check with Microsoft support and with VirtualBox support.

This configuration is sufficiently complex (Mac, Linux, Windows, VirtualBox guests, other devices, and presumably also some unspecified add-on hardware or software security-related apps) that you’re probably headed for a consulting engagement to address whatever concerns might be arising here, whether misconfigurations or routing issues or malware or otherwise, too.

So, which is it? In your other topic, you say you have an iPad. Now it's a laptop, which would be a MacBook (or Pro).

Since you say you're running Windows in VirtualBox, then it's a MacBook. And the same thing applies as in your other topic. Windows cannot, in any way, modify Apple's APFS drive format. The VM controls any data being passed from one OS to the other.

And that's all it is - data. You could copy millions of pieces of Windows malware onto your Mac's volume, and it can't do a thing. Wrong OS. Wrong hardware. None of it will run in macOS. Any malware hosing your Window install in the VM can only affect Windows. Though as you note, if you're low on disk space, RAM or such, then the slamming of inadequate hardware can cause errors. Nothing that is malware. Just not enough space or RAM for both Windows and macOS to run.