Detection rules › Splunk
Data Staged to File (Windows Event Log)
Adversaries may stage collected data in a central location or directory on the local system prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as Archive Collected Data. This use case looks for common output commands followed by a potential file extension
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Collection | T1074.001 Data Staged: Local Data Staging |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '5691.5953'
title: Data Staged to File
description: 'Adversaries may stage collected data in a central location or directory
on the local system prior to Exfiltration. Data may be kept in separate files or
combined into one file through techniques such as Archive Collected Data. This use
case looks for common output commands followed by a potential file extension. --
Threat Actor Association: Actinium/Gamaredon/Primitive Bear, APT29/Nobelium, APT37,
Arid Viper/APT C-23, Gorgon Group, Kimsuky, Memento Team, Wizard Spider, WIRTE --
Software Association: Bazar, Conti, Remcos - #TrendingThreat #Russia #Ukraine'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<")| regex Process_Command_Line="(?i)\s(\>(\>)?|Out\-File)\s.{1,}\.\w{2,5}"
| table _time, host, user signature_id, process, process_*, parent_* | bin span=1s
| stats values(*) as * by _time, host '
techniques:
- collection:data staged:local data staging
technique_id:
- T1074.001
data_category:
- Process command-line parameters
- Windows event logs
references:
- https://www.volexity.com/blog/2020/12/14/dark-halo-leverages-solarwinds-compromise-to-breach-organizations/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<")
Stage 2: regex
| regex Process_Command_Line="(?i)\s(\>(\>)?|Out\-File)\s.{1,}\.\w{2,5}"
Stage 3: table
| table _time, host, user signature_id, process, process_*, parent_*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
Process_Command_Line | regex_match |
|
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4688<" |