The following analytic identifies when the Active Directory Certificate Services store is backed up utilizing Event ID 4876. This event triggers whenever the backup occurs in the UI of CertSrv.msc or via CertUtil.exe -BackupDB occurs.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-02-06
- Author: Michael Haag, Splunk
- ID: a2f4cc7f-6503-4078-b206-f83a29f408a7
Kill Chain Phase
- CIS 10
1 2 3 4 5 `wineventlog_security` EventCode=4876 | stats count min(_time) as firstTime max(_time) as lastTime by dest, name, action, Caller_Domain ,Caller_User_Name | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_steal_authentication_certificates_cs_backup_filter`
The SPL above uses the following Macros:
windows_steal_authentication_certificates_cs_backup_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To implement this analytic, enhanced Audit Logging must be enabled on AD CS and within Group Policy Management for CS server. See Page 128 of first reference.
Known False Positives
False positives will be generated based on normal certificate store backups. Leave enabled to generate Risk, as this is meant to be an anomaly analytic. If CS backups are not normal, enable as TTP.
Associated Analytic Story
|40.0||50||80||The Active Directory Certiciate Services was backed up on $dest$.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1