Both of my Firefox based browsers (latest ESR and r3dfox) occasionally and without notice download a blank .HTM file to my download folder. Maybe once or twice a day. They all have a different random file name.
eg: yMHmvXVM.htm
I've checked my browser history to try and correlate when it happens with computer activity and it's never when I'm looking at the same site. Could be one of dozens that I visit regularly.
I've done full scans with my a/v and Malwarebytes and scanned the files online with multi-a/v scanners and they're ok.
Any ideas? Google doesn't help.
Doesn't seem to happen with other non-FF browsers.
EDIT: I'm going to disable my browser extensions/addons that I use on both browsers one at a time to see if that does anything.