Nope
Do you have this installed too? https://addons.mozilla.org/en-GB/firefox/addon/british-english-dictionary-2/
An Arch Linux user on Wednesday uploaded malicious AUR packages of firefox-patch-bin, librewolf-fix-bin, and zen-browser-patched-bin. These AUR packages ended up installing a binary file from a GitHub repository that ended up being a remote access trojan.
I take it Firefox sync between devices works all ok etc? Think its time to make the switch too.... :/