Fake Firefox survey

Running another cleaner perhaps wouldn't hurt but Malwarebytes Anti-Malware (MBAM)is a good program and has most likely completely got rid of the malware. I think all you can do now is keep a look out for any unusual computer behaviour.

The paid version of MBAM could be considered at some time. It is designed to run alongside the AV program and it adds another layer of realtime (monitoring/running in the background) security.

Also, have you ever heard of disk imaging? This can be a lifesaver if ever you get an infection so deep-seated that it is difficult to get rid of.

My Firefox put it in the spam folder and gave me a warning when it did!
Firefox works.

Malwarebytes was the one. It seemed to fix it.

Yes, I was very careful to avoid the free trial of the paid one. I've met that way of getting you signed up for an automatic update at the end of the trial period before.

The update window that I fell for was just today, so the malware has not been sitting around on my computer - and there was a warning in the form of a window informing me that something had tried to close down AVG in an unusual way.

What malware scanning program did you use? Malwarebytes Anti-Malware is a popular one. A lesser-known but often recommended program is AdwCleaner (links below):

Malwarebytes Anti-Malware
AdwCleaner

If installing Malwarebytes-Anti-Malware, read the options carefully and don't enable the free trial of the paid version ..and as usual, always go through the installation options of free programs carefully and un-tick any options to install unwanted software. I don't think there is any if the links above are used but it can't be guaranteed.

Regarding what antivirus program is best: As well as taking personal recommendations into account, it might also be helpful to take a look at the findings of a few AV program testing sites (links below). Although the results shown may be for security suites, the engines used are likely to be the same in the company's standalone AV programs ...free versions or paid.

AV-Comparatives
AV-Test (click 'Home User')
Virus Bulletin (click on the graph to enlarge)

Thank you stansgran

My computer man recommends Avast! and it does come up with useful warnings as DH is a great one for poking around on emails. He is beginning to learn to look before he leaps.

Further to this - after getting that "survey" I ran a malware search.

it turns out that I have added malware at some time by believing that a window saying "Time to update Firefox" - with what looked like a Firefox logo - and clicking on it. It called PUM.CHROME>EXTPOL and adds several files. The malware searcher had quarantined them. I am now trying to find put whether that is enough, or whather I have to do anything else.

Moral - always do updates direct from the application or from the manufacturer's legitimate website, don't believe a pop-up window.