Value of Firefox "permanent private browsing mode"

Privacy Questions
1

I use Firefox’s “permanent private browsing mode”, and I find it a bit inconvenient. I do this to not to increase privacy in particular, but to protect against a specific threat: Malware that can steal the login cookies from my disk, but not run a keylogger or read Firefox’s memory. (Reading memory should be hard, because I have YAMA blocking ptrace completely.)

It’s also helpful at limiting the blast area of a compromise, because there won’t be a ton of login cookies (that are difficult to even enumerate) which I have to invalidate.

But: If malware is “inside” Firefox, it could steal the cookies anyway, direct from memory. If malware can both steal files from my disk, and keylog me, it could have all my passwords direct from my password database. In either of these cases, permanent private browsing mode doesn’t help.

Is this actually a reasonable countermeasure, that addresses a worthwhile threat? Or am I just annoying myself for no real purpose?

2

Yes. See other threads about this.
I will add that if your main and only concern is browser security, choose Brave (Chromium). More secure.

1 Like
3

It works fine, but imo no reason not to use mullvad browser instead at that point. might as well reap all the benefits of that for basically the same inconvenience

4 Likes
4

I find less value in the permanent private browsing for logged in accounts because your malware problem can be solved by carefully inspecting mail attachments and avoiding suspicious sites in the internet.