6

This morning, running top, I noticed a process I nave never seen before in my Ubuntu 18.04 laptop called MainThread, which was periodically using a lot of CPU . There was also an entry called Privileged Cont.

I recently installed nordvpn, but nordvpn support said the process is not theirs. Is this a new part of the operating system? Is it malware? It has never appeared in top on my laptop before, as far as I know.

Zanna
  • 69,223
  • 56
  • 216
  • 327
Jim Giddings
  • 61
  • 3

3 Answers3

4

It is a change in recent firefox version (79+).

There is a bug about this.

kamaradclimber
  • 141
  • 3
2

In addition to other answers there is a problem I encountered killing Firefox.

Previously I could usesudo killall firefox. Now that has no effect and pgrep firefox finds nothing.

For me to kill an unresponsive Firefox session I now need to use:

sudo killall /usr/lib/firefox/firefox

Note above problem isn't limited to Ubuntu 18.04 as I'm using Ubuntu 16.04.6 LTS.

WinEunuuchs2Unix
  • 99,709
  • 34
  • 237
  • 401
1

Today I also saw that process and when I executed the kill command, firefox it closed immediately. When I re-opened Firefox the process reappeared, but when I killed Firerox's WebExtensions process, MainThread significantly reduced memory usage.

Zanna
  • 69,223
  • 56
  • 216
  • 327
José Miguel Palma
  • 11
  • 1
  • Thanks! It appears that ManThread is the new process name for Firefox. I don't understand why Firefox would substitute a cryptic name for an easily-understood one. In any case it's apparently not malware. – Jim Giddings Aug 05 '20 at 13:16