Snort mailing list archives
Re: HTTP Get Flood
From: Jamie Riden <jamie.riden () gmail com>
Date: Sun, 15 Feb 2015 16:13:19 +0000
I know this is snort list, so forgive me changing the subject slightly. Last time I dealt with anything on this scale (~12k hosts engaged in DoS by repeated HTTP GETs) we used fail2ban on the logs and fed this into the ipset fail2ban target to literally drop the traffic. (After we made this change, and about another day of hammering us and getting no particular effect, the attackers gave up. I don't think they were particularly sophisticated though.) Of course, you could equally well feed fail2ban from the snort logs and achieve the same thing that way rather than going off the apache logs as we were. However in DoS conditions, the quicker you can drop the traffic the better, so a "rude" DROP from iptables is preferred to a "polite" 403 message from Apache, and so on. cheers, Jamie On 15 February 2015 at 16:03, Mohammad Rastgoo <mohammad () synapti ca> wrote:
Hi, This is it: Srv PID Acc M CPU SS Req Conn Child Slot Client VHost Request 0-1 21953 0/75/3739 _ 0.87 3 128 0 0.28 42.46 92.50.31.242 www.domain.com:80 GET /moon HTTP/1.1 1-May 21977 1/39/3034 K 0.98 9 93 0.7 0.31 36.24 92.50.31.242 www.domain.com:80 GET /moon HTTP/1.1 13-1 21241 0/168/3311 _ 2.17 2 130 0 0.41 45.39 46.209.70.74 www.domain.com:80 GET /moon HTTP/1.1 15-1 22114 ######## K 0.18 11 93 0.7 0.05 20.92 46.209.70.74 www.domain.com:80 GET /moon HTTP/1.1 16-1 22186 0/14/3072 _ 0.63 11 88 0 0.1 32.13 46.209.70.74 www.domain.com:80 GET /moon HTTP/1.1 19-1 20925 0/114/2514 _ 2.49 12 88 0 0.35 30.51 46.209.70.74 www.domain.com:80 GET /moon HTTP/1.1 20-1 22275 0/3/3303 _ 0.3 5 129 0 0.02 31.76 46.209.13.250 www.domain.com:80 GET /moon HTTP/1.1 On Sun, Feb 15, 2015 at 9:00 AM, Al Lewis (allewi) <allewi () cisco com> wrote:Hello, Can you provide a sample of the rule/conf you are trying to use as well as a pcap of the offending traffic? The section on uricontent is here: http://manual.snort.org/node32.html#SECTION004523000000000000000 Make sure you are not trying to match on content before its normalized as listed in the manual: “The uricontent keyword in the Snort rule language searches the NORMALIZED request URI field. This is equivalent to using the http_uri modifier to a content keyword. As such if you are writing rules that include things that are normalized, such as %2f or directory traversals, these rules will not alert.” Hope this helps. Albert Lewis QA Software Engineer SOURCE*fire*, Inc. now part of *Cisco* 9780 Patuxent Woods Drive Columbia, MD 21046 Phone: (office) 443.430.7112 Email: allewi () cisco com *From:* Mohammad Rastgoo [mailto:mohammad () synapti ca] *Sent:* Saturday, February 14, 2015 7:42 PM *To:* snort-sigs () lists sourceforge net *Subject:* [Snort-sigs] HTTP Get Flood Hi, Thanks for reading this. My site has been receiving attacks for a while now and I've been able to stop them using snort + pfsense. Most of them were stopped just by using uri-content in the rule. Today I've been receiving Get attacks on the main page. It really seems too simple but any rule I have tried has not blocked any IP addresses. Would someone please guide me to the right direction? Thanks-- Mohammad Rastgoo Founder & CEO ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Snort-sigs mailing list Snort-sigs () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-sigs http://www.snort.org Please visit http://blog.snort.org for the latest news about Snort!
-- Jamie Riden / jamie () honeynet org / jamie.riden () gmail com http://uk.linkedin.com/in/jamieriden
------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
_______________________________________________ Snort-sigs mailing list Snort-sigs () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-sigs http://www.snort.org Please visit http://blog.snort.org for the latest news about Snort!
Current thread:
- HTTP Get Flood Mohammad Rastgoo (Feb 14)
- Re: HTTP Get Flood Al Lewis (allewi) (Feb 15)
- Re: HTTP Get Flood Mohammad Rastgoo (Feb 15)
- Re: HTTP Get Flood Jamie Riden (Feb 15)
- Re: HTTP Get Flood Al Lewis (allewi) (Feb 15)
- Re: HTTP Get Flood Al Lewis (allewi) (Feb 15)
- Re: HTTP Get Flood Mohammad Rastgoo (Feb 15)
- Re: HTTP Get Flood Al Lewis (allewi) (Feb 15)