It's amazing that in nearly-2015, enough people still use passwords like '123456' and 'password' such that they're still at the top of the guessing list in hacking attempts. Some of us will never learn, I guess...
Not exactly a famous site, but I thought a larger sample size might be interesting...
We [1] provides shared hosting for about 500 WordPress installations, of widely varying sizes. The sites are mostly static "blogs" for student groups or individual students, with about half on a single domain (www.ocf.berkeley.edu/~something) and others on different subdomains of berkeley.edu.
In the past week, the webserver handled 3,527,157 requests (about 814 MB of uncompressed access logs). 111,409 of those were WordPress login attempts [2].
I was going to compare the list of top IPs with the list in the article, but was surprised to find that there were no shared IPs between the lists. For context, we had 435 unique IPs, 9 with > 1000 requests, and 32 with > 100 requests.
The top ten requestors in the past week are from (cities from whois data):
56742 Kiev, Ukraine
19302 Novosibirsk, Russia
7645 Sofia, Bulgaria
7641 Moscow, Russia
7190 Kiev, Ukraine
6748 Kharkov, Ukraine
2160 Roubaix, France
1041 Kharkov, Ukraine
967 Kuala Lumpur, Malaysia
894 Putian, China
[2] POST requests to wp-login.php. I don't have accurate numbers on how many failed, but to say that less than 250 were legitimate user logins is probably accurate.
The cause for this is the belief that Google gives more weight to content and backlinks from these TLDs.
Like this article closes with though, non "admin" accounts and strong passwords foil all these lame automated attempts. (I suspect one day it'll get attacked by someone with a Wordpress zeroday, and I'll have to reprovision the vm from scratch - Yay Ansible! - come at me scriptkiddies!)
I looked up Wordfence. The way it preemptively blocks attacks from all domains that attack any Wordfence user's site is pretty clever.
(Alternatively, you can just update the password hash for the existing user account.)