I have just fallen for the "Urgent Firefox Update" scam, and not only downloaded the JavaScript but run it! It was when this opened a terminal window and started running something that I realised it was some sort of malware. At this point, I disconnected my computer from the Internet and ran Malwarebytes. This detected three suspicious files which I quarantined. The corresponding Malwarebytes log is attached.
I then, following the advice at: https://malwaretips.com/blogs/remove-fake-urgent-firefox-update-virus/
ran AdwCleaner and HitmanPro (see HitmanPro_20170705_1523.log) which deleted a whole bunch of cookies and an executable which I believe to be, in fact, benign (it has been on my system without causing problems for a year or more). I then updated and reran Malwarebytes, which then found no threats.
My concern is whether I can safely continue to use the machine, or if there is anything I can do to ensure that there is no residual threat lurking somewhere. I'm running the latest version of Windows 10 on a Microsoft surface pro 3.
In case this is relevant the source of the rogue software (retrieved from my browsing history) appears to be
https://odahxvisitezmonsite.com/2051415340379/1499254195619138/firefox-update.js
and
https://odahxvisitezmonsite.com/2051415340379/1499254195619138/firefox-patch.js
Immediately prior to receiving the "Urgent Firefox Update" message the webpage I was on was https://www.thoughtco.com/photoshop-clone-stamp-tool-tutorial-1697534
Any advice would be welcome!
malware.txt
HitmanPro_20170705_1523.log