This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

I just received a warning that Mozilla was scanning my computer and had found a virus. I have a Mac. I this this must be bogus. Does Firefox ever scan?

  • 10 cavab
  • 26 have this problem
  • 2 views
  • Last reply by perryrc

more options

I was on the Apple Support community forum and followed a link . WOT add on said safe, but all of a sudden a pop-up? said Mozilla was running a scan and found a virus and a trojan. However, it was scanning windows files which I don't have (I have an iMac). I closed the tab immediately and went to Safari to pose this question there. Then went back to Firefox, the same link and clicked it and it happened again. I am sure it was bogus (now that I am calm) but wondered if this has happened to anyone else. I haven't done a google search on it yet. The fact that it mentioned Mozilla was very disconcerting since I believe this is very trustworthy.

I was on the Apple Support community forum and followed a link . WOT add on said safe, but all of a sudden a pop-up? said Mozilla was running a scan and found a virus and a trojan. However, it was scanning windows files which I don't have (I have an iMac). I closed the tab immediately and went to Safari to pose this question there. Then went back to Firefox, the same link and clicked it and it happened again. I am sure it was bogus (now that I am calm) but wondered if this has happened to anyone else. I haven't done a google search on it yet. The fact that it mentioned Mozilla was very disconcerting since I believe this is very trustworthy.

All Replies (10)

more options

That's a fake scan, Firefox doesn't do "security scans".

more options

I didn't think so. It was very freakish though. And happened twice. I didn't download or install anything so I am sure I am okay and since it said it was scanning windows files, I knew it had to be phony. But in this day and age it is easy to get scared about these things and never hurts to double check. I switched to Firefox from Safari because I like its features generally better, but makes me wonder if I should switch back again. Until there is a problem there and I'm back here again. Its like musical browsers

more options

Such a scan is an animation that is loaded from the server. I assume that you saw a scan of a Windows file system and that is impossible because you are on a Mac.

You may be visiting a web site that has been infected or is hosting malware.

more options

Thank you for your reply. Someone else had a similar experience. And I'm pretty sure it must have been a pop up or something like that and that it was an animation. Especially since it was showing a scan of a Windows file system which i obviously don't have. I had this happen before on a pc but was just surprised when it happened on the mac. I tend to be usually on the cautious side and don't download or install anything I'm not sure about, but as I said it is very disconcerting. I can understand how people get scared and then get taken by these tricks. Just reminds me to be suspicious. I use the WOT (web of trust) add on. And it did not alert me that the website was untrustworthy. It may have been a site that is normally okay, but itself been hacked some how.

Thanks again for your response.

more options

I just received the same type of warning. Unfortunately I clicked ok to scan thinking it was a valid Firefox function. It actually went through what looked like a scan and then said it found several viruses and then recommended using an antivirus software. When I clicked cancel it tried to download an .exe file saying Firefox recommends this download and wouldn't let me leave that box. (I had to close out the tab to get it to exit) I was sooooo worried and then I found your post and now I can relax.

After I read your post I remembered that an .exe file was a Windows based file. I didn't let it download anyway, but I just feel so much better after reading your message and the replies. Thanks you sooooo much for posting the information!!

You didn't mention that you'd received the download box like I did, so I thought I'd reply not only to thank you, but to let others know to be aware that this is happening and to be cautious when getting attempts to download unknown files making it look like Firefox is attempting to download antivirus software.

more options

I too am a Happy Mac User and am glad that my posting helped you. I first posted on the Apple Support Communities forum and got a lot of reassurance from the users there. If you want to look at it, it is in the Using Apple Support Discussion Community. To let you know that I too was sooooo worried, my question there started with Help! I didn't do the whole scan because I saw quickly that they were windows files. As long as you didn't install anything you are okay. But yeah, the fact that it starts by telling you that Firefox is recommending it gives it just a bit more credence. Glad that my posting helped you.

more options

I've got this problem too and it seem to occur when I try to download pictures. I'm on a Mac. I've never seen it before but now it occurs repeatedly and it is very difficult to escape from it without turning off Firefox and restart it. Can I get rid of the whole problem in some way???

more options

Snigel, I'm not sure how to get rid of it since I didn't download anything, but I do know that on the Apple Support Discussion forum there has recently been a lot of activity about a trojan which has been trying to get installed on different Macs. You might want to check there. Go to Mac OS X System Software and then Mac OS X v10.6 Snow Leopard Community and see if it is the same thing that you are dealing with. MacDefender? or something like that. Good luck.

more options

I've had the same problem when running a google image search, then running into these pesky faux scan pop-ups when clicking on an image to view. It's happened more than a few times in the recent past but a force quit and restart usually resolve the matter. Using Mac OS X 10.5.8 and the most recent version of Firefox. I forgot how I was able to get the scan window to disappear upon subsequent Firefox restarts which is why I'm on this forum today. I've force quit Firefox 3 times but each time I restart that faux scan window greets me - I can't get it to go away even after restarting the computer. Any suggestions?

more options

There is a lot of information on the Apple Support Communities about how to get rid of that trojan, if that is what it is. I was lucky that what I had was different I think, but there are several places now that have information on how to uninstall it. I've seen it on the 10.6 Snow Leopard community so you might try looking there.