mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
75 lines
3.3 KiB
YAML
75 lines
3.3 KiB
YAML
name: WinRM Spawning a Process
|
|
id: a081836a-ba4d-11eb-8593-acde48001122
|
|
version: 2
|
|
date: '2024-05-20'
|
|
author: Drew Church, Michael Haag, Splunk
|
|
status: experimental
|
|
type: TTP
|
|
description: The following analytic detects suspicious processes spawned by WinRM
|
|
(wsmprovhost.exe). It leverages data from Endpoint Detection and Response (EDR)
|
|
agents, focusing on specific child processes like cmd.exe, powershell.exe, and others.
|
|
This activity is significant as it may indicate exploitation attempts of vulnerabilities
|
|
like CVE-2021-31166, which could lead to system instability or compromise. If confirmed
|
|
malicious, attackers could execute arbitrary commands, escalate privileges, or maintain
|
|
persistence, posing a severe threat to the environment.
|
|
data_source:
|
|
- Sysmon EventID 1
|
|
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
|
|
as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=wsmprovhost.exe
|
|
Processes.process_name IN ("cmd.exe","sh.exe","bash.exe","powershell.exe","pwsh.exe","schtasks.exe","certutil.exe","whoami.exe","bitsadmin.exe","scp.exe")
|
|
by Processes.dest Processes.user Processes.parent_process Processes.process_name
|
|
Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)`
|
|
| `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `winrm_spawning_a_process_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: Unknown. Add new processes or filter as needed. It is possible
|
|
system management software may spawn processes from `wsmprovhost.exe`.
|
|
references:
|
|
- https://github.com/SigmaHQ/sigma/blob/9b7fb0c0f3af2e53ed483e29e0d0f88ccf1c08ca/rules/windows/process_access/win_susp_shell_spawn_from_winrm.yml
|
|
- https://www.zerodayinitiative.com/blog/2021/5/17/cve-2021-31166-a-wormable-code-execution-bug-in-httpsys
|
|
- https://github.com/0vercl0k/CVE-2021-31166/blob/main/cve-2021-31166.py
|
|
tags:
|
|
analytic_story:
|
|
- CISA AA23-347A
|
|
- Rhysida Ransomware
|
|
- Unusual Processes
|
|
asset_type: Endpoint
|
|
confidence: 50
|
|
cve:
|
|
- CVE-2021-31166
|
|
impact: 50
|
|
message: tbd
|
|
mitre_attack_id:
|
|
- T1190
|
|
observable:
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
required_fields:
|
|
- _time
|
|
- Processes.dest
|
|
- Processes.user
|
|
- Processes.parent_process
|
|
- Processes.process_name
|
|
- Processes.process
|
|
- Processes.process_id
|
|
- Processes.parent_process_id
|
|
risk_score: 25
|
|
security_domain: endpoint
|