Detection: Splunk Identified SSL TLS Certificates

Description

The following analytic identifies the usage of Splunk default SSL/TLS certificates within the environment. It leverages tags such as SSL, TLS, and certificate to detect these default certificates by examining the ssl_issuer_common_name field. This activity is significant because using default certificates can expose the environment to potential security risks, as they are not unique and can be easily exploited. If confirmed malicious, attackers could intercept or manipulate data, leading to unauthorized access or data breaches. It is recommended to replace default certificates with valid, unique TLS certificates to enhance security.

Search

1tag IN (ssl, tls, certificate) ssl_issuer_common_name=*splunk* 
2| stats values(src) AS "Host(s) with Default Cert" count by ssl_issuer ssl_subject_common_name ssl_subject_organization ssl_subject host sourcetype 
3| `splunk_identified_ssl_tls_certificates_filter`

Data Source

Name	Platform	Sourcetype	Source
Splunk Stream TCP	Splunk	'stream:tcp'	'stream:tcp'

Macros Used

| splunk_identified_ssl_tls_certificates_filter | search * |

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

Ingestion of SSL/TLS data is needed and to be tagged properly as ssl, tls or certificate. This data may come from a proxy, zeek, or Splunk Streams. Splunk SOAR customers can find a SOAR workbook that walks an analyst through the process of running these hunting searches in the references list of this detection. In order to use this workbook, a user will need to run a curl command to post the file to their SOAR instance such as "curl -u username:password https://soar.instance.name/rest/rest/workbook_template -d @splunk_psa_0622.json". A user should then create an empty container or case, attach the workbook, and begin working through the tasks.

Known False Positives

False positives will not be present as it is meant to assist with identifying default certificates being utilized.

Associated Analytic Story

• Splunk Vulnerabilities

Risk Based Analytics (RBA)

References

• https://docs.splunk.com/Documentation/Splunk/8.2.6/Security/AboutsecuringyourSplunkconfigurationwithSSL

• https://www.github.com/splunk/security_content/blob/develop/workbooks/splunk_psa_0622.json

Detection Testing

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 3