On my mac, in activity process, there are two processes that keep on running even though I stop them. They are AddressBookSourceSync and com.apple.AddressBook.ContactsAccountsService. Is it possible that they are viruses or am I just being paranoid. How do I quit these? I tried everything but it keeps turning back on.

  • Have you tried force quitting them or restarting the computer? AddressBookSourceSync is a built-in Apple program relating to the address book (contacts) application
    – NoahL
    Jun 8, 2016 at 15:30
  • @NoahL Yes I force quitted, restarted but it is still there. Can you tell me what it is supposed to do? Maybe I can tell you if it is supposed to be running. I can't find much info on the internet. And the thing is I have never used the contacts application on my mac.
    – user187535
    Jun 8, 2016 at 15:33
  • Let me know if this doesn't help you out: discussions.apple.com/thread/3355782?start=45&tstart=0
    – NoahL
    Jun 8, 2016 at 15:36

1 Answer 1


Taken from one of the answers in this Apple Communities thread:

  • Export all contacts to a vCard file for safe keeping.

  • Delete Library --> Application Support --> Address Book.

  • Reboot.

  • Open System Preferences --> iCloud. Enable Contact Syncing.

  • What question or problem is this supposed to solve?
    – samh
    Oct 7, 2017 at 20:17

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