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splunk-security_content/detections/endpoint/batch_file_write_to_system32.yml
2022-03-09 14:43:09 +01:00

87 lines
3.1 KiB
YAML

name: Batch File Write to System32
id: 503d17cb-9eab-4cf8-a20e-01d5c6987ae3
version: 2
date: '2021-09-16'
author: Michael Haag, Rico Valdez, Splunk
type: TTP
datamodel:
- Endpoint
description: The search looks for a batch file (.bat) written to the Windows system
directory tree.
search: '| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
where Processes.process_name=* by _time span=1h Processes.process_id Processes.process_name
Processes.dest | `drop_dm_object_name(Processes)` | join process_guid, _time [|
tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path IN ("*\\system32\\*",
"*\\syswow64\\*") Filesystem.file_name="*.bat" by _time span=1h Filesystem.dest
Filesystem.file_create_time Filesystem.file_name Filesystem.file_path | `drop_dm_object_name(Filesystem)`
| fields _time dest file_create_time file_name file_path process_name process_path
process] | dedup file_create_time | table dest file_create_time, file_name, file_path,
process_name | `batch_file_write_to_system32_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information
on process that include the name of the process responsible for the changes from
your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
endpoint product.
known_false_positives: It is possible for this search to generate a notable event
for a batch file write to a path that includes the string "system32", but is not
the actual Windows system directory. As such, you should confirm the path of the
batch file identified by the search. In addition, a false positive may be generated
by an administrator copying a legitimate batch file in this directory tree. You
should confirm that the activity is legitimate and modify the search to add exclusions,
as necessary.
references: []
tags:
analytic_story:
- SamSam Ransomware
asset_type: Endpoint
cis20:
- CIS 8
confidence: 90
context:
- Source:Endpoint
- Stage:Execution
dataset:
- https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1204.002/batch_file_in_system32/windows-sysmon.log
impact: 70
kill_chain_phases:
- Delivery
message: A file - $file_name$ was written to system32 has occurred on endpoint $dest$
by user $user$.
mitre_attack_id:
- T1204
- T1204.002
nist:
- PR.PT
- DE.CM
observable:
- name: user
type: User
role:
- Victim
- name: dest
type: Hostname
role:
- Victim
- name: file_name
type: File Name
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- Filesystem.dest
- Filesystem.file_name
- Filesystem.user
- Filesystem.file_path
- Processes.process_id
- Processes.process_name
- Processes.dest
risk_score: 63
security_domain: endpoint
supported_tas:
- Splunk_TA_microsoft_sysmon