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My site is being attacked and is using up all the RAM. I looked at the Apache logs and every malicious hit seems to simply be a POST request on /, which is never required by a normal user.

So I thought and wondered if there's any sort of solution or utility that will monitor my Apache logs and block every IP that performs a POST request on the site root. I'm not familiar with DDoS protection and searching didn't seem to give me an answer, so I came here.

Thanks.

Example logs:

103.3.221.202 - - [30/Sep/2012:16:02:03 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (iPad; CPU OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
122.72.80.100 - - [30/Sep/2012:16:02:03 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11"
122.72.28.15 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"
210.75.120.5 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20100101 Firefox/12.0"
122.96.59.103 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (Linux; U; Android 2.2; fr-fr; Desire_A8181 Build/FRF91) App3leWebKit/53.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1"
122.96.59.103 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (Linux; U; Android 2.2; fr-fr; Desire_A8181 Build/FRF91) App3leWebKit/53.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1"
122.72.124.3 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:13.0) Gecko/20100101 Firefox/13.0.1"
122.72.112.148 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.1" 302 485 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0) Gecko/20100101 Firefox/13.0.1"
190.39.210.26 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.0" 302 485 "-" "Mozilla/5.0 (Windows NT 6.0; rv:13.0) Gecko/20100101 Firefox/13.0.1"
210.213.245.230 - - [30/Sep/2012:16:02:04 +0000] "POST / HTTP/1.0" 302 485 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"
101.44.1.25 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
101.44.1.28 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
101.44.1.28 - - [30/Sep/2012:16:02:14 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
103.3.221.202 - - [30/Sep/2012:16:02:13 +0000] "POST / HTTP/1.1" 302 466 "-" "Mozilla/5.0 (iPad; CPU OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
211.161.152.104 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
101.44.1.25 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11"
101.44.1.25 - - [30/Sep/2012:16:02:11 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11"
211.161.152.105 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6"
211.161.152.105 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; MRA 5.8 (build 4157); .NET CLR 2.0.50727; AskTbPTV/5.11.3.15590)"
211.161.152.105 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; MRA 5.8 (build 4157); .NET CLR 2.0.50727; AskTbPTV/5.11.3.15590)"
101.44.1.25 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11"
101.44.1.25 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
211.161.152.108 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (iPad; CPU OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
101.44.1.28 - - [30/Sep/2012:16:02:13 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
211.161.152.106 - - [30/Sep/2012:16:02:11 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:5.0.1) Gecko/20100101 Firefox/5.0.1"
103.3.221.202 - - [30/Sep/2012:16:02:13 +0000] "POST / HTTP/1.1" 302 466 "-" "Mozilla/5.0 (iPad; CPU OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3"
101.44.1.28 - - [30/Sep/2012:16:02:11 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
211.161.152.105 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; MRA 5.8 (build 4157); .NET CLR 2.0.50727; AskTbPTV/5.11.3.15590)"
211.161.152.104 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
211.161.152.104 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
211.161.152.105 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6"
101.44.1.25 - - [30/Sep/2012:16:02:10 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11"
122.72.124.2 - - [30/Sep/2012:16:02:17 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
122.72.124.2 - - [30/Sep/2012:16:02:11 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
122.72.124.2 - - [30/Sep/2012:16:02:17 +0000] "POST / HTTP/1.1" 302 522 "-" "Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1"
210.213.245.230 - - [30/Sep/2012:16:02:12 +0000] "POST / HTTP/1.0" 302 522 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)"

iptables -L:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination   

-

bui@debian:~$ sudo iptables -I INPUT 1 -m string --algo bm --string 'Keep-Alive: 300' -j DROP
iptables: No chain/target/match by that name.
bui@debian:~$ sudo iptables -A INPUT -m string --algo bm --string 'Keep-Alive: 300' -j DROP
iptables: No chain/target/match by that name.
share|improve this question
    
You said it's "using up all the RAM". What is using up all the RAM? The correct response to this DDoS will depending on what is happening to your server. For instance, if your application is trying to process the request, even though it doesn't know what to do with it, that is what is using up your RAM. Seeing that some of those requests took over 5 seconds to run, sysadmin1138's suggestion will very likely work. –  Ladadadada Oct 1 '12 at 9:09

3 Answers 3

I advise you to install mod_security. Please update your question with what type of system you have so I can add instructions on how to install it.

Also in your firewall stop incoming ping packets.

share|improve this answer
    
While mod_security is not bad advice, this answer needs some work before I can upvote it. It could do with a rule or set of rules that would block this attack. Incoming pings are not his problem and blocking them will not fix anything. While the logs he pasted don't match the HOIC defaults, this could easily be HOIC or a variant. That link is a great place to start analysing the attack and figuring out how to block it. –  Ladadadada Oct 1 '12 at 9:19

Use fail2ban. You can define the pattern and it will make iptables rules according that.

share|improve this answer
    
+1 for best answer. This isn't any more "right" than making iptables rules manually, but fail2ban is much easier to admin. Just make sure you don't ban your own logins via SSH...this happened to me (forgot my password before Monday coffee...it was a bad day). –  Zac B Sep 30 '12 at 17:34

You may be served by putting in a limit to prevent post from the root. Especially if it is "never required by a normal user."

In an .htconfig in your root directory:

<LimitExcept GET>
 Require valid-user
</LimitExcept>

Which will tell it to require a logged-in user for any method but a simple GET (more details). Or if you just want to ban POST at the top:

<Limit POST>
  Deny from all
</Limit>

This will throw a 403-forbidden message, which should tell the scanners to not bother.

To remove the limit, in a directory where you actually want to allow POST:

<Limit POST>
  Allow from all
</Limit>
share|improve this answer
    
It's not scanners; it's a botnet that will just hit the page no matter what response code it receives. Sending a 403 won't help as Apache is still paying attention to it, so I need a way to prevent the IPs from connecting to the server -- something like iptables. –  Mark Sep 30 '12 at 16:26

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