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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.

  • Type: Hunting

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-23
  • Author: Michael Haag, Splunk
  • ID: 620fbb89-86fd-4e2e-925f-738374277586

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1040 Network Sniffing Credential Access, Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 13
CVE 


1
2
3



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

Macros

The SPL above uses the following Macros:

:information_source: splunk_identified_ssl_tls_certificates_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • ssl_issuer
  • ssl_subject_common_name
  • ssl_subject_organization
  • ssl_subject
  • host
  • sourcetype

How To Implement

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

RBA

Risk Score Impact Confidence Message
42.0 60 70 The following $host$ is using the self signed Splunk certificate.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 2