What is "AddressBookUrlForwarder"?

Question

Today I clicked a link on Facebook and a dialogue window gave me the message:

"The link needs to be opened with an application. Send to:
AddressBookUrlForwarder

Upon examining the link, it had the format:

fb://photo/12345678?set=blahblahlblah

I've never seen a browser link with the "fb://" protocol before and certainly never heard of "AddressBookUrlForwarder".

So I did a finder search and came up with nothing. Then I did a Locate search from terminal and found:

/System/Library/CoreServices/AddressBookUrlForwarder.app

So I open "/System/Library/CoreServices/" in finder and that app doesn't show up. But it's definitely there. Thinking it must have some extended attributes or ACL I do an "ls-lae@" in the coreservices directory and for all intents and purposes it appears to be a normal .app directory with no @ or + or anything special to hide it from the Finder.

What the heck is going on? What is this app? Why is it not showing up in Finder? What is an "fb://" protocol link?

I'm creeped out now.

Also, I'm using 10.8.4.

Answer 1

I'm guessing that this application is used to retrieve Facebook and Twitter contact details for display in the address book.

This assumption is based on release notes for a recent update of Mac OS X, as well as the content of that application's executable (as viewed with strings):

strings /System/Library/CoreServices/AddressBookUrlForwarder.app/Contents/MacOS/AddressBookUrlForwarder`).

The output of strings makes me think that the application is a URL handler for these expressions:

...
_urlPatterns
http://www.facebook.com/profile.php?id=$1
fb://profile/(.*)
http://twitter.com/$1
twitter:///user[?]screen_name=(.+)
http://twitter.com/share?text=$1
twitter:///post[?]message=(.+)
...

Do you have a Facebook account setup in System Preferences -> Mail, Contacts & Calendars?