:no_entry: THIS IS A DEPRECATED DETECTION

This detection has been marked deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported.

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Description

Enforcing network-access controls is one of the defensive mechanisms used by cloud administrators to restrict access to a cloud instance. After the attacker has gained control of the console by compromising an admin account, they can delete a network ACL and gain access to the instance from anywhere. This search will query the Change datamodel to detect users deleting network ACLs. Deprecated because it's a duplicate

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

  • Last Updated: 2020-09-08
  • Author: Peter Gael, Splunk
  • ID: 021abc51-1862-41dd-ad43-43c739c0a983

Annotations

ATT&CK
Kill Chain Phase
  • Actions on Objectives
NIST
  • DE.DP
  • DE.AE
CIS20
  • CIS 11
CVE
1
2
3
4
5
6
`cloudtrail` eventName=DeleteNetworkAcl
|rename userIdentity.arn as arn  
| stats count min(_time) as firstTime max(_time) as lastTime values(errorMessage) values(errorCode) values(userAgent) values(userIdentity.*) by src userName arn eventName 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `cloud_network_access_control_list_deleted_filter`

Macros

The SPL above uses the following Macros:

:information_source: cloud_network_access_control_list_deleted_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.

  • _time
  • eventName
  • userIdentity.arn
  • errorMessage
  • errorCode
  • userAgent
  • src
  • userName
  • arn

How To Implement

You must be ingesting your cloud infrastructure logs from your cloud provider. You can also provide additional filtering for this search by customizing the cloud_network_access_control_list_deleted_filter macro.

Known False Positives

It's possible that a user has legitimately deleted a network ACL.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 tbd

: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: 1