LAB-3.md

Lab 3

Table of Contents

• Reporting Security Events
• Create a Splunk Alert
• Dashboard Challenge

Advanced Splunk Search and Dashboards

In this lab we will be performing more complex searches and adding to our security dashboard.

Resources:

• http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Search
• http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Rex
• http://regexr.com/
• http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Stats
• http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Eval

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Reporting Security Events

Create a report showing when Rails Goat file upload mechanism is abused to perform command injection.

1. Login to Splunk by opening the Splunk Console with your browser. Splunk Console: https://54.186.140.211/en-US/account/login?return_to=%2Fen-US%2F

2. Click on Search & Reporting and search for your instance's Rails Goat logs, these should be under the main index. E.g., index=main host=<Private DNS> source="/home/ec2-user/railsgoat/log/mysql.log". Select All time from the time range picker and click Search.

3. Search for events containing filename. Do you see any events? If not, go back to Week 3 Lab 3 and do Exercise 2.

4. Pipe the current search results to rex to extract the injected command into a new field named cmd. Do NOT use the field extractor UI (+ Extract New Fields) for this exercise.

Example: if my event returns something like ...filename=\"test.rtf;+mkdir+pwn\"\r\nContent-Type:... I am interested in capturing everything between the first plus-sign and the following back-slash, i.e., mkdir+pwn.

Hint 1: | rex " filename=(?<cmd>.*) .*". Hint 2: escaping back-slashes within rex is special, you need 3 back-slashes to escape one back-slash.

5. Pipe the results to another rex command to substitute the plus-signs (+) with spaces ( ).

To do this you will need to 1) filter on the cmd field (| rex field=cmd), 2) put rex in sed mode (see resources above) and 3) substitute the plus-sign with a space using a sed style regular expression, e.g., "s/\+/ /g".

6. Use the stats command to display the values of cmd by host.

7. Save the search as a report. Click Save As > Report and enter <STUDENT ID> - Cmd Injection as the report title and click Save. Click Add to Dashboard, select Existing and select the dashboard you created during the last lab. Click Save and click View Dashboard.

Create a Splunk Alert

Create a Splunk alert that will trigger when Rails Goat file upload mechanism is abused to perform command injection.

1. Go to reports, open the report you just created. Select Edit > Open in Search

2. Modify the timeframe for the current search from All time to Last 60 minutes. You can do this by selecting time range picker, choose Last 60 minutes and click search.

3. From the upper-right select Save As > Alert. Use these values for the following fields: Title: <STUDENT ID> - Cmd Injection, Schedule: Run every hour, select the next closest interval to the current time from 0, 15, 30, 45 for the minutes past the hour selector. Click + Add Actions > Add to Triggered Alerts and select High for the Severity. Click Save and close the dialog by clicking x on the upper-right.

Dashboard Challenge

Using knowledge gained during previous labs, add two additional panels to your new dashboard as per the following specification:

1. HTTP Codes. A pie chart displaying the distribution of HTTP codes returned by Rails Goat.

2. A panel showing SQL injections / SQL errors. This is a report which extracts SQL related errors in Rails Goat.

See: