In the last few days, my system has started popping up an Ubuntu default web-browser and making a request to nmcheck.gnome.org website and immediately shutting off.

Since this happened, I cannot run system updates.

Also, I am a php developer and cannot run composer install or composer update

sudo apt update

software update

How can I find this script and delete it forever?

  • Chech which plugin's / add-on's there are installed in your browser(s).
    – Soren A
    Aug 31, 2018 at 10:41
  • I am using Firefox and I already disabled each extension but it is not opening Firefox it is using Ubuntu default browser Aug 31, 2018 at 10:43
  • 1
    What leads you to believe that "Ubuntu software update blocked my IP"? Please answer questions by editing your original question. Comments are not intended for conversation.
    – user535733
    Aug 31, 2018 at 13:41
  • Most Linux distributions come with Firefox installed and set as the default browser.
    – NickT
    Aug 31, 2018 at 13:49
  • sudo lsof -i will show internet connections. Adding namechk.com to your /etc/hosts with an IP of will prevent the connection.
    – waltinator
    Aug 31, 2018 at 13:50

4 Answers 4


on Ubuntu 20.04 no [Connectivity] line like accepted answer in /etc/NetworkManager/NetworkManager.conf.

But you can disable the auto connectivity check by:

  1. Go to Settings app
  2. Go to Privacy menu
  3. On Connectivity tab, uncheck Connectivity Checking
  • 1
    Actually there is, if you type NetworkManager --print-config you'll see that option, it's just that's inside /etc/NeworkManager/conf.d/20-connectivity.conf.
    – Emanuele
    Jun 3, 2022 at 12:08

nmcheck.gnome.org is not malware. It is the gnome network manager connectivity check (for captive portals/hotspots). Click the link and you will see a single text file with a text in it. It should be "NetworkManager is online".

Check /etc/NetworkManager/NetworkManager.conf. There probably is a section with this in it:

  • any suggestion why software update is not running? Aug 31, 2018 at 19:31
  • 2
    This feature is weird Jul 29, 2020 at 4:32
  • 3
    No such line in NetworkManager.conf. and my popup happens on a standard always-live RJ45-to-router-to-large-ISP connection. imgur.com/a/hTQ2aiu Oct 23, 2020 at 7:25
  • please do not use rules for Ubuntu 18.04 for 20.04 ;-) It probably is set differently in 20.04
    – Rinzwind
    Oct 23, 2020 at 7:55
  • It should at least use SSL.
    – bakcsa83
    Oct 28, 2020 at 11:21

nmcheck.gnome.org is a host used by NetworkManager to verify that it has Internet connectivity. gnome.org is owned by the Gnome project. This is not a suspicious domain.

nmcheck.gnome.org hosts a single file; network_status.txt, which indicates that NM is actually connected to the Internet.

In short, nothing to worry over.

  • 2
    but it is alway popup around 5 minutes and this is occurring all of a sudden still I can not update software see image That I have attached Aug 31, 2018 at 19:24
  • any suggestion why software update is not running? Aug 31, 2018 at 19:31
  • 1
    I suggest that you ask your actual question, and not what you imagine the problem to be. Make a new question (or edit the current one) about why updates fail.
    – vidarlo
    Aug 31, 2018 at 19:31

This is painful when connecting to public or free hotspots, of course until you "log on" there is no DNS so this always fails.

It can also pop up during modem/router boots or when the wifi NIC has issues.

If it happens at the same time every day then something is going offline or rebooting. Maybe a firmware push check.

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