Files
splunk-security_content/detections/endpoint/wermgr_process_create_executable_file.yml
2023-03-03 12:40:16 +01:00

62 lines
2.2 KiB
YAML

name: Wermgr Process Create Executable File
id: ab3bcce0-a105-11eb-973c-acde48001122
version: 1
date: '2021-04-19'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: this search is designed to detect potential malicious wermgr.exe process
that drops or create executable file. Since wermgr.exe is an application trigger
when error encountered in a process, it is really un ussual to this process to drop
executable file. This technique is commonly seen in trickbot malware where it injects
it code to this process to execute it malicious behavior like downloading other
payload
data_source:
- Sysmon Event ID 1
search: '`sysmon` EventCode=11 process_name = "wermgr.exe" TargetFilename = "*.exe"
| stats min(_time) as firstTime max(_time) as lastTime count by Image TargetFilename
process_name dest EventCode ProcessId | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
| `wermgr_process_create_executable_file_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
logs with the process name, parent process, and command-line executions from your
endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
Sysmon TA. Tune and filter known instances of wermgr.exe may be used.
known_false_positives: unknown
references:
- https://labs.vipre.com/trickbot-and-its-modules/
- https://whitehat.eu/incident-response-case-study-featuring-ryuk-and-trickbot-part-2/
tags:
analytic_story:
- Trickbot
asset_type: Endpoint
confidence: 80
impact: 70
message: Wermgr.exe writing executable files on $dest$
mitre_attack_id:
- T1027
observable:
- name: dest
type: Endpoint
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- Image
- TargetFilename
- process_name
- dest
- EventCode
- ProcessId
risk_score: 56
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/trickbot/infection/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: xmlwineventlog