My last try offered safe mode or refresh. safe mode loaded the same malware page, so I selected refresh next time. Of course all previous open tabs are lost. Is there any way to recover them other than going back through history manually?

Hi blindleader, you can try converting your old session history file to a page of links and then reload the tabs when needed.

The session history files would now be here:

[Desktop]\Old Firefox Data\profile.folder\sessionstore-backups

My converter is here:

https://www.jeffersonscher.com/ffu/scrounger.html

After you load the .jsonlz4 file to the page, click Scrounge URLs to extract the list.

It's also theoretically possible to load your old file in your current Firefox profile, but the results will depend on your settings (and I have to end this message now).