Detection: Detect Certify Command Line Arguments

Updated Date: 2024-12-10 ID: e6d2dc61-a8b9-4b03-906c-da0ca75d71b8 Author: Steven Dick Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the use of Certify or Certipy tools to enumerate Active Directory Certificate Services (AD CS) environments. It leverages Endpoint Detection and Response (EDR) data, focusing on specific command-line arguments associated with these tools. This activity is significant because it indicates potential reconnaissance or exploitation attempts targeting AD CS, which could lead to unauthorized access or privilege escalation. If confirmed malicious, attackers could gain insights into the AD CS infrastructure, potentially compromising sensitive certificates and escalating their privileges within the network.

Search

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process IN ("* find *","* auth *","* request *","* req *","* download *",) AND Processes.process IN ("* /vulnerable*","* /enrolleeSuppliesSubject *","* /json /outfile*","* /ca*", "* -username *","* -u *") by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)`
6| `detect_certify_command_line_arguments_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Sysmon EventID 1	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Windows Event Log Security 4688	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
detect_certify_command_line_arguments_filter	`search *`

detect_certify_command_line_arguments_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1649	Steal or Forge Authentication Certificates	Credential Access
T1105	Ingress Tool Transfer	Command And Control

Command and Control

Exploitation

DE.CM

CIS 10

Default Configuration

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

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Certify/Certipy arguments detected on $dest$.

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	90	process_name

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

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: 5