On a Windows 10 machine, is it safer to run the Linux version of a browser using Windows Subsystem for Linux instead of running the Windows version?
I'm asking because I've read the Wikipedia article on Windows Subsystem for Linux (WSL), and I'm not sure of how it works security-wise. It says that
WSL provides a Linux-compatible kernel interface developed by Microsoft (containing no Linux kernel code), which can then run a Linux userland on top of it
WSL uses fewer resources than a fully virtualized machine
Is this Linux userland well separated from the Windows one? That is, is the WSL a sort of virtual machine, isolated from the rest of the system? Assuming I use the Linux version of Firefox to visit a malicious website which fully compromises it, would the malware's effectiveness be reduced by being confined in this WSL, or would the result be the same as having the native Firefox for Windows compromised?
Or, to put it differently: if I want an isolated system that I can use to visit potentially insecure sites, is it enough to use WSL, or do I need a full-fledged virtual machine?
I've found a similar question, but it is about the attack surface, that is, before the system is compromised. Instead, I'm asking whether WSL implies any mitigations after the system has been compromised. Moreover, that question was asked before WSL was released, and some details weren't clear back then.