I was also click-bombed on 2 sites with completely different niches the only thing in common is that they're both forums.
I was click-bombed by the following ips:
209.51.197.x
207.182.128.x
207.182.132.x
209.190.31.x
5.101.146.x
94.229.76.218
88.150.131.58
173.209.49.90
68.168.114.42
I decided to block the following CIDR address ranges on my server:
209.51.197.0/24 = XLHost.com Inc
207.182.128.0/19 = XLHost.com Inc
209.190.0.0/17 = XLHost.com Inc
5.101.144.0/21 = UK Dedicated Servers Limited / STA005-IP1
94.229.64.0/20 = UK Dedicated Servers Limited / STA005-IP1
173.209.49.0/24 = GTCOMM-2650
88.150.131.0/24 = RSDEDI-GPAANOOP / UK
173.209.49.0/24 = GTCOMM-2650
68.168.114.0/24 = GTCOMM-2650
90% of the attacks came from XlHost and STA005-IP1 entworks using different ip ranges so I do recommend to block the whole CIDR address range for this networks.
I was able to identify this attack because this bots leave the following signature on the webserver logs:
"Mozilla/5.0 (Windows NT 6.2; WOW64; rv:27.0)"
My adsense earnings went up around 300% because of this attack.
I already reported this to google; I hope they don't cancel my account...
Hope this helps..
[edited by: rveram at 7:07 am (utc) on Apr 20, 2015]