Suricata don`t mutch http post request with my rule

I writed this rule:

alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"HTTP POST packet flood"; http.method; content:"POST"; detection_filter: track by_dst, count 3, seconds 10;)

but Suricata don`t mutch post packets and dont log it. Help please

Hi, can you help us with some info about:

  • what command are you using to run Suricata
  • which version are you using
  • do you see any errors when Suricata starts?


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I use this command for start:

sudo suricata -i enp0s3

I use 6.0.3 version
No, I dont have any errors

I`m generating POST request by ab:

ab -T application/x-www-form-urlencoded -p /tmp/body -n 1000 

in suricata.log I see, what packets arrived at the server

It would be good to know:

  • Are you sure Suricata is capturing/receiving that specific traffic?
  • If yes, how? pcap, nfqueue, ipfw divert?
  • Is there a test rule to make sure the detection is working fine?
  • How is your suricata.yaml configured? (HOME_NET)

I’ve replicated your scenario with the test rule below:

alert http $EXTERNAL_NET any -> 80 (msg:"HTTP packet"; http.method; content: "POST"; detection_filter: track by_dst, count 3, seconds 10;)

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  1. Yes, I shure
  2. How it to know?
  3. No and I dont know how to write it
  4. изображение_2021-11-04_235629

how did you generate post request?

  1. Post request gerenated with ab (same parameters).

  2. To make sure a rule is matching try to simplify the rule options at a time. In your case, start with matching just post request and test the rule if it works and each time add more options (track…).

3) Your HOME_NET range is wide, so be sure the host sending post resquest is not part of the home networks as the rule is matching requests from EXTERNAL_NET (out of your HOME_NET) to HOME_NET (internal networks).

A simple rule that can be used to check if Suricata is detecting things as expected could be:
alert icmp any any -> any any (msg: "ICMP Packet found"; sid: 1000002; rev: 1;)

Then you can try and use a ping command to trigger it.

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