SIEM Integration Overview: Splunk

Install From SplunkBase

Navigate to the GreyNoise App on Splunkbase and download the GreyNoise TA.

COMPATIBILITY MATRIX

• Splunk Enterprise version: 9.0.x, 8.2.x, 8.1.x, 8.0.x
• OS: Platform independent
• Vendor Products: GreyNoise API

RELEASE NOTES (VERSION 2.2.1)

• Updated to support Splunk Cloud requirements

RELEASE NOTES (Version 2.2.0)

• Added new FEED component to create lookuptable based on GreyNoise indicators
• Added new command gnipsimilar and new Similar IP Lookup dashboard
• Added new command gniptimeline and new IP Timeline Lookup dashboard
• Updated gnenrich command to use batch lookups
• Updated gnquery command with new parameters page_size and exclude_raw
• Updated GreyNoise SDK to v2.0.1

RELEASE NOTES (Version 2.1.5)

• Fix bug with gnenrich, gnriot, and gnfilter where proxy wasn't being used for API key validation
• Fix credentials.py to deal with null API keys on fresh install

RELEASE NOTES (Version 2.1.4)

• Add support for configuring proxy information in conf file
• Add support for IP Destination Geo feature fields
• Fix bug in gnriot when IPv6 address is sent for lookup
• Update to use GreyNoise SDK 1.3.0
• Update to use splunktaucclib 6.0.6

RELEASE NOTES (Version 2.1.2)

• Fixed issue where API key could not be entered on new installs
• IMPORTANT: GreyNoise API Key must be re-entered if upgrading from a previous version

RELEASE NOTES (Version 2.1.1)

• Fixed JQuery 3.5.0 compatibility issue identified via Upgrade Readiness
• Fixed Python3 compatibility issue identified via Upgrade Readiness
• Fixed missing explict definition for cache_maintenance script to use py3
• Update to use GreyNoise SDK 1.2.0
• Updated splunklib to version 1.6.18

RELEASE NOTES (Version 2.1.0)

• Python2 and Splunk7.x support is dropped starting from this release, GreyNoise now only supports Splunk 8.x and Python3
• Updated to latest GreyNoise SDK 1.1.0
• Added gnriot custom command for the RIOT endpoint
• Improves error messages for non-routable and invalid IP address
• Updated splunklib to version 1.6.16
• Updated the time in gnoverview saved search to 6 hours
• Added 2 new codes to the csv file
• Updated the custom commands, saved searches, and dashboards to handle the RIOT key
• Fixed an issue to handle Splunk fields with unallowed characters
• Added Caching feature for all the custom commands and saved searches.

Topology and Setting Up Splunk Environment

Standalone Mode

• Install GreyNoise App for Splunk. See the INSTALLATION section for more details.
• Configure the API key and log level. See the CONFIGURATION section for details.

Search Head Cluster

• In case of Search Head Clustering, make sure that the GreyNoise Setup and Scan Deployment is configured on only a single search head. In such cases, the configuration will not be visible on other search heads. If a user wants to configure Logging (default is INFO), the user can configure it individually on every search head (recommended).
• If user wants to replicate the configuration settings, follow these steps:
• On search head deployer, extract the app at $SPLUNK_HOME$/etc/shcluster/apps.
• Create stanza shclustering at path $SPLUNK_HOME$/etc/shcluster/apps/app-greynoise/local/server.conf and add following information to the stanza: conf_replication_include.app_greynoise_settings = true
• Push the bundle to search head.
• Configure the API key and log level. See the CONFIGURATION section for details. Following these steps will replicate the configuration on all search heads.

Permissions

Configuration can only be done by admin but other custom commands can be used by admin and the users with list_storage_passwords capability.

Installation

Follow the below-listed steps to install an app from the bundle:

• Download the App package.
• From the UI navigate to Apps > Manage Apps.
• In the top right corner select Install app from file.
• Select Choose File and select the App package.
• Select Upload and follow the prompts.
• Restart the Splunk to complete the installation.
  Note: This app contains Adaptive Response Actions, which can be used along with Splunk Enterprise Security. To use these alert actions on the Splunk instance without Splunk Enterprise Security, kindly install Splunk Common Information Model (CIM).

UPGRADING FROM VERSION 2.0.1

Follow the below steps to upgrade the app to the latest version:

• Disable all the saved searches which uses alert actions and custom commands of GreyNoise.
• Backup your current app/configurations outside of the Splunk install path.
• To upgrade the app from the UI, follow the steps in the INSTALLATION section below. Ensure that Upgrade app. checkbox is selected before clicking on the Upload button.
• Follow the steps mentioned in CONFIGURATION section to reconfigure the app.
• If SCAN DEPLOYMENT feature was already configured before app upgradation then go to SCAN DEPLOYMENT tab inside the Configuration tab and Click on Save button to re-configure the scan deployment saved search in the backend.

Note: Upgrade is only supported from UI and not supported from the backend.

Configure GreyNoise Integration Instance

Configuration

The app can be configured in the following way:

• From the Splunk UI navigate to Apps > GreyNoise App for Splunk > Configuration.
• Click on GreyNoise Setup and enter the API Key.
• Click on the Save button.
• The app is now configured and all the features (except Scan Deployment) are ready to be used.

Logging

Users can configure the log level by navigating to Apps > GreyNoise App for Splunk > Configuration and selecting Logging.

Caching

This feature helps user to enable/disable caching for all the custom commands and saved searches. It can be configured in the
following way:

• From the Splunk UI navigate to Apps > GreyNoise App for Splunk > Configuration.
• Click on Caching.
• Enter the following details to set up the Caching:
• Enable caching: Checkbox to enable caching for all custom commands and savedsearches.
• Time to live: Time period (in hours) to configure the cache’s time to live. Responses whose age is greater than the TTL, will be removed from the cache by a savedsearch which will run every hour.
• Purge Cache: Checkbox to purge the cache of all responses.

Proxy Support

To enable proxy support, modify the app_greynoise_settings.conf and add a proxy entry to the parameters section.

Example:
[parameters]
proxy = http://proxy.acme.com:8080

Scan Deployment

This feature helps users to scan the Splunk Deployment and identify the noise IP addresses from it. It can be configured in the following way:

• From the Splunk UI navigate to Apps > GreyNoise App for Splunk > Configuration.
• Click on Scan Deployment.
• Enter the following details to set up the Scan Deployment:
• Indexes: Indexes to be scanned in the deployment.
• CIM Fields: CIM fields containing IP address to scan for noise status.
• Other Fields: Other comma(,) separated fields containing IP address to scan for noise status.
• Scan Start Time: Time range for scanning the indexed Splunk data.
• Enable Scan Deployment: Checkbox to enable or disable scanning of the deployment.
• Force Scan Deployment: This is useful when the user wants to override the current running scan immediately and start a new one.

Feed

This feature allows users to ingest GreyNoise indicators into a lookup table to be used within the Splunk environment :

• From the Splunk UI navigate to Apps > GreyNoise App for Splunk > Configuration.
• Click on Feed Configuration tab.
• Enter the following details to set up the Feed:
  • Enable Feed Import: turns the feature on to enable the daily ingest of GreyNoise indicators via feed
  • Force Feed Run Now: starts a manual run of the feed import, rather than waiting for the daily scheduled run
  • Feed Selection: select the appropriate option to choose which type of feed to ingest into the system

🚧

Ensure your subscription includes a Feed license before enabling.

On-Demand Commands

The following commands are included as a part of the app:

gnip

Search format:
| gnip ip="(ip_address)"

Purpose: Retrieves context information for a given IP address from the GreyNoise.

gnquick

Search format:
| gnquick ip="(ip_address),(ip_address),(ip_address)"
SPL_QUERY | gnquick ip_field="(ip_field)"

Purpose: Retrieve the noise status of all the IP addresses as separate events [OR] Retrieve the noise status for all the given IPs returned by the SPL_QUERY for specified ip_field.

gnquery

Search format:
| gnquery query="(GNQL_query)" result_size="(result_size)"

Purpose: Retrieve the results of the given GNQL query from GreyNoise. result_size denotes the number of results to be retrieved which is capped at 50,000. result_size is an optional parameter with a default value of 50,000.

gnstats

Search format:
| gnstats query="(GNQL_query)" count="(stats_count)"

Purpose: Fetch the aggregate statistics for the top organizations, actors, tags, ASNs, countries, classifications, and operating systems of all the results for a given GNQL query. count denotes the number of stats to be retrieved. count is an optional parameter.

gnmulti

Search format:
SPL_QUERY | gnmulti ip_field="(ip_field)"

Purpose: Retrieves noise status of the IP addresses represented by ip_field parameter present in each event, and adds the noise information to each event.

gncontext

Search format:
| gncontext ip="(ip_address)"

Purpose: Retrieves context information for a given IP address from the GreyNoise.

gnfilter

Search format:
SPL_QUERY | gnfilter ip_field="(ip_field)" noise_events="(true/false)"

Purpose: Filter Splunk events returned by given SPL_QUERY based on the noise status of IP address present in ip_field of the events. noise_events is an optional parameter with a default value of true. So, it will return events with noise IP addresses by default.

gnenrich

Search format:
SPL_QUERY | gnenrich ip_field="(ip_field)"

Purpose: Enrich the Splunk events returned by given SPL_QUERY with the context information of IP address represented by ip_field in Splunk Search.

gnriot

Search format:
| gnriot ip="<ip_address>" [OR] SPL_QUERY | gnriot ip_field="<ip_field>"

Purpose: Retrieves RIOT information for a given IP address from the GreyNoise [OR] Retrieves RIOT information for all the given IPs returned by the SPL_QUERY for specified ip_field.

gniptimeline

Search format:
| gniptimeline ip_address="<ip_address>" days= limit=

Purpose: Retrieves Timeline information for a given IP address from the GreyNoise Timeline API.

gnipsimilar

Search format:
| gnipsimilar ip_address="<ip_address>" min_score=<min_score> limit=

Purpose: Retrieves Similarity information for a given IP address from the GreyNoise Similarity API.

Note: While executing the transforming commands from Splunk search UI, ensure that the event count passed to the command is less than 50,000, as per standard limits of Splunk. If the event count is higher than this number, the user can create a Saved Search and pass a higher number of Splunk statistical data to the command.

Alert Actions

The following alert actions are included as a part of the app:

• GreyNoise Quick Check: Returns noise information from GreyNoise for given IP addresses.
• GreyNoise Context Check: Returns context information from GreyNoise for given IP Addresses.

These alert actions can be used independently as well as with Splunk Enterprise Security in the form of Adaptive Response Actions. Results from these actions can be found in index=main sourcetype=greynoise

The two sources for these adaptive response actions are:

• source=greynoise_context
• source=greynoise_quick

Usage with Splunk Enterprise Security:

These actions can be executed from Incident Review, and results can be accessed directly by refreshing the "Adaptive Responses" panel and clicking the appropriate link.

Workflow Action

Identify Noise workflow action is enabled for all the CIM compliant IP fields which can be used to fetch the context information for the corresponding IP addresses.

Dashboard

This app contains the following three dashboards:

• Overview: This dashboard represents an overall visualization of the statistics provided by the GreyNoise platform as well as the statistics of the noise IPs in the Splunk deployment.

• Noise IP Addresses: This dashboard displays all the IP addresses along with their noise status scanned by GreyNoise through the Scan Deployment feature in the current Splunk deployment. This dashboard will be populated when the Scan Deployment feature is enabled.

• Live Investigation: This dashboard can be used to obtain context information fetched dynamically from the GreyNoise platform based on the form input provided. This is the same as performing a GNQL in the GreyNoise Visualizer or API.

Saved Searches

This app contains the following saved searches, which are used for populating data in the dashboard:

• greynoise_scan_deployment_once: Used to populate gn_scan_deployment_ip_lookup lookup and is triggered after configuring Scan Deployment feature.
• greynoise_scan_deployment: Used to populate gn_scan_deployment_ip_lookup lookup and is triggered at an interval of 60 minutes and scans the data of the previous 70 minutes.
• greynoise_overview_once: Used to populate gn_overview_lookup lookup, and is triggered after configuring the API key.
• greynoise_overview: Used to populate gn_overview_lookup lookup, and is triggered at an interval of 30 minutes.
  Note: greynoise_scan_deployment_once and greynoise_scan_deployment saved searches are used for scanning the data indexed in Splunk. So, in the case when these saved searches are skipped, the data indexed during that interval will not be scanned for noise status.

Troubleshooting

Issue: Scan Deployment Indexes List Missing Indexes

In the case where the Scan Deployment Indexes drop-down does not contain all of the expected indexes, and when the Splunk system contains multiple search heads, it is required that an indexes.conf file is added to the local directory of the GreyNoise Splunk App with a list of all the desired indexes. This will then force the drop-down to contain the desired indexes.