Splunk Search

Show events with certain frequency

ernestpoon
New Member

Hi guys, I have an Apache log (with only few information) and I would like to find out the possible events related to brute force password attack.

I am considering to find the login page access records which happened rapidly within three seconds. For example (just an example), if there are the following events:

127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:35 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:35 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:34 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:34 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:33 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:32 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:32 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:20:36 -0700] "GET /config.php HTTP/1.0" 200 2326 "http://www.example.com/dashboard.php"
127.0.0.1 - frank [10/Oct/2000:13:10:00 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:20 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:20 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:19 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:18 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"

The result will be:
127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:35 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:35 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:34 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:34 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:33 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:32 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:55:32 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:20 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:20 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:19 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"
127.0.0.1 - frank [10/Oct/2000:13:08:18 -0700] "GET /login.php HTTP/1.0" 200 2326 "http://www.example.com/login.php"

What should the code be?
I will be able to count the number of password attack occur and plot a time chart showing the attack pattern, after solving this problem.
Thanks.

0 Karma

dkeck
Influencer

HI,

did you try to use | timechart count span=3s ? This will give you a lot of spikes in timechart graph but it will group your events in a 3 s intervall. You should only use this with a short time periode

0 Karma

mayurr98
Super Champion

Hi can you try this :

Number of Password Attacks:

index=<your_index> | rex field=_raw "\s"(GET|POST|DELETE|UPDATE)\s\/(?<Access>[^\.]+)" | search Access=login | stats count as "Password Attacks"

Plotting it in Timechart:

index=<your_index> | rex field=_raw "\s"(GET|POST|DELETE|UPDATE)\s\/(?<Access>[^\.]+)" | search Access=login | timechart span=3s count as "Password Attacks"

change span according to your need.
let me know if this helps!

0 Karma

ernestpoon
New Member

Hi, thank you for your advice. timechart span=3s count as "Password Attacks" is useful! However, it seems that the rex part has some mistakes so there's an error telling me "Search Factory: Unknown search command 'post'."

0 Karma

mayurr98
Super Champion

Try this :

index=<your_index> | rex field=_raw "\s\"GET\s\/(?<Access>[^\.]+)" | search Access=login | timechart span=3s count as "Password Attacks"
0 Karma

ernestpoon
New Member

The error disappeared. But no result is shown.
I am now trying specify the url_path instead of using regular expression. However, I cannot save the timechart to a dashboard. Do you know why?

0 Karma
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Splunk Cloud Application Management in Terraform

Now On-Demand   We’re diving into how you can bring Infrastructure as Code (IaC) principles to your Splunk ...

What's New in Splunk Enterprise Security (ES) 8.6

Purpose-Built AI Agents for the Agentic SOC  Splunk Enterprise Security 8.6 expands AI in Security with ...

From Raw Data to Executive-Ready Stories, Faster

Build Data Stories for Every Audience  A dashboard is rarely just a dashboard. It might be the view an ...