I am trying to use /etc/hosts on my mac to block infamous scumbag sites like mackeeper.com and com-cleaner.systems from ever loading again in popups.

While doing that I've found these entries on my hosts file:

# Host Database
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##        localhost  broadcasthost
::1              localhost

so I have added these...  mackeeper.com  www.mackeeper.com  mackeeperapp.zeobit.com  mackeeperapp2.mackeeper.com  *.mackeeper.com  activate.adobe.com  practivate.adobe.com  *.com-cleaner.systems  *.bet.pt

and all these sites continue to load fine even after a restart.

I have tried also adding the same lines with fe80::1%lo0 and ::1 without success.

Any ideas?

  • 1
    Though this will not answer your question, you could install some pop-up blocker extension plus an ad-blocker. – LinuxSecurityFreak Dec 10 '17 at 19:22
  • Please edit question with contents of /etc/nsswitch.conf. – dirkt Dec 10 '17 at 20:40
  • 4
    Wildcards like *.bet.pt will not work in /etc/hosts. – Ulrich Schwarz Dec 10 '17 at 20:45
  • @UlrichSchwarz - brilliant. The problems were the wildcards. Please convert your comment to an answer so I can accept. – SpaceDog Dec 10 '17 at 21:55

macOS has a DNS cache, and if the IP addresses of the problem sites are already in your DNS cache, editing /etc/hosts won't have an immediate effect.

The procedure for flushing the DNS cache is annoyingly version-dependent:


  • 10.4: lookupd -flushcache
  • 10.5, 10.6: dscacheutil -flushcache
  • 10.7, 10.8: sudo killall -HUP mDNSResponder
  • 10.9: dscacheutil -flushcache; sudo killall -HUP mDNSResponder
  • 10.10.1 .. 10.10.3: sudo discoveryutil udnsflushcaches
  • 10.10.4+: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
  • 11: sudo killall -HUP mDNSResponder
  • 12+: sudo killall -HUP mDNSResponder; sudo killall mDNSResponderHelper; sudo dscacheutil -flushcache
|improve this answer|||||
  • Thank you for actually including the solution for people who (like me) haven't upgraded past 10.4! – Fox Dec 13 '17 at 20:21
  • I've learned that it's useful to quote the essential parts of a linked solution, in case the linked article goes away someday. This way the answer will also work stand-alone even if the link becomes outdated. – telcoM Dec 13 '17 at 23:13

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