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

Multiple Firefox processes in task manager due to Virus/Malware

  • 1 cavab
  • 2 have this problem
  • 9 views
  • Last reply by cor-el

more options

Hello. About a week ago I have downloaded a malicious file, which, after using, started to open new Firefox windows every few seconds and downloading various programs like amazon app etc. Thus I disabled the internet and then used at least 5 different anti-malware programs as well as couple anti-virus programs that detected and removed various malware. Afterwards, I had no such problems, but I still had some BITSADMIN cmd.exe appearing, after doing some research I found that this is a command line created by the malware, but it seems to do nothing now, as the malware is removed. And then I noticed I have multiple Firefox windows on my task manager, every time, the real one can be recognized by expanding the process, then it shows the open tabs. The "BAD" one though, is always there, starting at about 50MB of memory usage then "growing" up to 300MB+ in some time... I did some more research, uninstalled Firefox, fully, and then reinstalled it, but the problem continues. I do not have any other ideas what to do further, maybe you could assist me with this? Note that I have used all of the most popular and freely/trial based available anti-malware and anti-virus programs.

Hello. About a week ago I have downloaded a malicious file, which, after using, started to open new Firefox windows every few seconds and downloading various programs like amazon app etc. Thus I disabled the internet and then used at least 5 different anti-malware programs as well as couple anti-virus programs that detected and removed various malware. Afterwards, I had no such problems, but I still had some BITSADMIN cmd.exe appearing, after doing some research I found that this is a command line created by the malware, but it seems to do nothing now, as the malware is removed. And then I noticed I have multiple Firefox windows on my task manager, every time, the real one can be recognized by expanding the process, then it shows the open tabs. The "BAD" one though, is always there, starting at about 50MB of memory usage then "growing" up to 300MB+ in some time... I did some more research, uninstalled Firefox, fully, and then reinstalled it, but the problem continues. I do not have any other ideas what to do further, maybe you could assist me with this? Note that I have used all of the most popular and freely/trial based available anti-malware and anti-virus programs.

All Replies (1)

more options

In current Firefox releases is multi-process tabs enabled. This means that see more than one Firefox process running (one for the main browser process and one for the content process). You can see this on the "Help -> Troubleshooting Information" page (Application Basics: Multiprocess Windows).

You can disable multi-process tabs in Firefox by setting the related prefs to false on the about:config page.

  • browser.tabs.remote.autostart = false
  • browser.tabs.remote.autostart.2 = false

See also: