Writeup from 2022 that I assume is mostly still valid. TLDR:
- Mainstream Linux is less secure than macOS, Windows, and ChromeOS. (Elsewhere: “[iOS/Android] were designed with security as a foundational component. They were built with sandboxing, verified boot, modern exploit mitigations and more from the start. As such, they are far more locked down than other platforms and significantly more resistant to attacks.”)
- Move as much activity outside the core maximum privilege OS as possible.
- OP doesn’t mention immutable OS, but I assume they help a lot.
- Create a threat model and use it to guide your time and money investments in secure computing.
Once you have hardened the system as much as you can, you should follow good privacy and security practices:
- Disable or remove things you don’t need to minimise attack surface.
- Stay updated. Configure a cron job or init script to update your system daily.
- Don’t leak any information about you or your system, no matter how minor it may seem.
- Follow general security and privacy advice.
I’ve had a hot take for a while now that Linux isn’t “more secure” than other operating systems like a lot of evangelists will claim. I think people get this impression because the user base for desktop Linux has been small enough that no one was writing malware targeted at us.
Unix’s security model was developed in a world where the primary concern was protecting the system from users and protecting users from each other. It wasn’t really designed for single-user systems where the main concern is protecting the user from their own applications.
Probably not true now. It took some digging but I found e.g. BPFdoor https://attack.mitre.org/software/S1161/ which “does not need root to run” https://sandflysecurity.com/blog/bpfdoor-an-evasive-linux-backdoor-technical-analysis
The silver lining is that a lot of these backdoors are nation-state level so you might not be targeted by them. If I had data on my computer worth a dang, I’d be more concerned.