I randomly selected .edu websites from all over the web, including edu.az, edu.com.tr etc. 62 of 100 had those hacklinks.
Good find.
Do you have any hypotheses about a common vector for the hack? In addition to run-of-the-mill vectors, there's also the possibility that educational middleware (online class management a la Sungard, Blackboard, PeopleSoft) is vulnerable -- this is pure speculation, of course, but as someone who worked with dozens of those portals it piques my curiosity.