mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Gowthamaraj rajendran
88 lines
4.2 KiB
YAML
88 lines
4.2 KiB
YAML
name: Windows SQL Spawning CertUtil
|
|
id: dfc18a5a-946e-44ee-a373-c0f60d06e676
|
|
version: 1
|
|
date: '2023-08-25'
|
|
author: Michael Haag, Splunk
|
|
status: experimental
|
|
type: TTP
|
|
data_source:
|
|
- Sysmon Event ID 1
|
|
description: The following analytic detects the use of certutil to download software,
|
|
a behavior exhibited by the threat actor Flax Typhoon. This actor deploys a VPN
|
|
connection by downloading an executable file for SoftEther VPN from their network
|
|
infrastructure using one of several LOLBins, including certutil. The actor then
|
|
uses the Service Control Manager (SCM) to create a Windows service that launches
|
|
the VPN connection automatically when the system starts. This behavior allows the
|
|
actor to monitor the availability of the compromised system and establish an RDP
|
|
connection. This analytic identifies this behavior by monitoring for the use of
|
|
certutil in conjunction with the downloading of software. This behavior is worth
|
|
identifying for a SOC as it indicates a potential compromise of the system and the
|
|
establishment of a persistent threat. If a true positive is found, it suggests an
|
|
attacker has gained access to the environment and is attempting to maintain that
|
|
access, potentially leading to further malicious activities such as data theft or
|
|
ransomware attacks. Be aware of potential false positives - legitimate uses of certutil
|
|
in your environment may cause benign activities to be flagged. Upon triage, review
|
|
the command executed and look for concurrent processes to identify the attack source.
|
|
This approach helps analysts detect potential threats earlier and mitigate the risks.
|
|
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
|
|
as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name
|
|
IN ("sqlservr.exe", "sqlagent.exe", "sqlps.exe", "launchpad.exe", "sqldumper.exe")
|
|
`process_certutil` (Processes.process=*urlcache* Processes.process=*split*) OR Processes.process=*urlcache*
|
|
by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name
|
|
Processes.process_name Processes.process Processes.process_id Processes.original_file_name
|
|
Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
|
|
| `security_content_ctime(lastTime)` | `windows_sql_spawning_certutil_filter`'
|
|
how_to_implement: 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: The occurrence of false positives should be minimal, given
|
|
that the SQL agent does not typically download software using CertUtil.
|
|
references:
|
|
- https://www.microsoft.com/en-us/security/blog/2023/08/24/flax-typhoon-using-legitimate-software-to-quietly-access-taiwanese-organizations/
|
|
tags:
|
|
analytic_story:
|
|
- Flax Typhoon
|
|
asset_type: Endpoint
|
|
atomic_guid: []
|
|
confidence: 100
|
|
impact: 90
|
|
message: $process_name$ was launched on $dest$ by $user$. This behavior is uncommon
|
|
with the SQL process identified.
|
|
mitre_attack_id:
|
|
- T1105
|
|
observable:
|
|
- name: dest
|
|
type: Endpoint
|
|
role:
|
|
- Victim
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Target
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
risk_score: 90
|
|
required_fields:
|
|
- Processes.dest
|
|
- Processes.user
|
|
- Processes.parent_process
|
|
- Processes.parent_process_name
|
|
- Processes.process_name
|
|
- Processes.process
|
|
- Processes.process_id
|
|
- Processes.original_file_name
|
|
- Processes.parent_process_id
|
|
security_domain: endpoint
|