I am used to finding some random probing from script bots in my apache log files, but today I found some strange entries:
18.104.22.168 - - [25/Apr/2014:01:52:36 +0000] "GET /calendar/caldetail/id/281/num/1328144400 HTTP/1.1" 404 439 "-" "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)" 22.214.171.124 - - [05/Apr/2014:06:19:08 +0000] "GET /media/u1485/album/pic_1485_3218_original.jpg HTTP/1.1" 404 443 "-" "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)"
There were numerous other entries similar to these.
The strange thing is that it looks like they originated either from Facebook or Microsoft servers. Both provide identifying information as well as IP addresses that appear to belong to the aforementioned organizations.
I do not have any URLs that look even close to those found in the GET requests. To give some background, I bought the domain something like a month ago and AFAIK it was not used before.
Can anyone shed some light on the possible causes of these requests?