WordNet (r) 3.0 (2006):

fortune cookie
    n 1: thin folded wafer containing a maxim on a slip of paper

The Jargon File (version 4.4.7, 29 Dec 2003):

fortune cookie
 n.

    [WAITS, via Unix; common] A random quote, item of trivia, joke, or maxim
    printed to the user's tty at login time or (less commonly) at logout time.
    Items from this lexicon have often been used as fortune cookies. See 
    cookie file.


The Free On-line Dictionary of Computing (30 December 2018):

fortune cookie

   (WAITS, via the Unix "fortune" program) A quotation, item
   of trivia, joke, or maxim selected at random from a collection
   (the "cookie file") and printed to the user's tty at login
   time or (less commonly) at logout time.

   There was a fortune program on TOPS-20.

   [First program?]

   [Jargon File]

   (1995-02-14)