Comment spammers aren’t the sharpest knives in the draw. If they did their research properly they’d realise that spamming here was a stupid as trying to burgle the police station (while it’s open). You’ll notice there’s no comment spam around here, but that isn’t to say they don’t try.
Anyway, there’s been a lot of activity lately from a spambot running at an “interesting” hosting company called Volumedrive. They rent out rack space, so it’s not going to be easy for them to know what their customers are doing, but they don’t seem inclined to shut any of them down for “unacceptable” use. For all I know they’ve got a lot of legitimate customers, but people do seem to like running comment spammers through their servers.
If you need to get rid of them, there is an easy way to block them completely if you’re running WordPress, even if you don’t have full access to the server and its firewall. The trick is to over-ride the clients Apache is prepared to talk to (default: the whole world) by putting a “Deny from” directive in the .htaccess file. WordPress normally creates a .htaccess file in its root directory; all you do is add:
Deny from bad.people.com
Here, “bad.people.com” is the server sending you the spam, but in reality they probably haven’t called themselves anything so convenient. The Apache documentation isn’t that explicit unless you read the whole lot, so it’s worth knowing you can actually list IP addresses (more than one per line) and even ranges of IP addresses (subnets).
Deny from 188.8.131.52
Deny from 184.108.40.206 220.127.116.11
Deny from 18.104.22.168/24
The last line blocks everything from 22.214.171.124 to 126.96.36.199. If you don’t know why, please read up on IP addresses and subnet masks (or ask below in a comment).
So when you get a a load of spammers from similar IP addresses, look up to see who the block belongs to using “whois”. Once you know you can block the whole lot. For example, if you’re being hit by the bot using Volumedrive on 188.8.131.52, run “whois 184.108.40.206”. This will return:
NetRange: 220.127.116.11 - 18.104.22.168
NetType: Direct Allocation
If you don’t have whois on your comptuer (i.e. you’re using Windoze) there’s a web version at http://www.whois.net/.
In the above, the CIDR is the most interesting – it specifies the block of IP addresses routed to one organisation. I’m not going in to IP routing here and now, suffice to say that in this example it specifies the complete block of addresses belonging to volumedrive that we don’t want – at least until they clean up their act.
To avoid volumedrive’s spambots you need to add the following line to the end your .htaccess file:
Deny from 22.214.171.124/20
If this doesn’t work for you the the web server you’re using may have been configured in a strange way – talk to your ISP if they’re the approachable type.
I have contacted Volumedrive, but they declined to comment, or even reply; never mind curtail the activities of their users.
This isn’t a WordPress-only solution – .htaccess belongs to Apache and you can use it to block access to any web site.
Perhaps there’s some scope in sharing a list these comment spambots in an easy-to-use list. If anyone’s interested, email me. This is a Turing test :-)