Detection rules › Splunk
Fsutil fsinfo execution (Windows Event Log)
Adversaries may attempt to gather information about attached peripheral devices and components connected to a computer system. Peripheral devices could include auxiliary resources that support a variety of functionalities such as keyboards, printers, cameras, smart card readers, or removable storage. This use case looks for when fsutil is executed with fsinfo
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1120 Peripheral Device Discovery |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '8150.10002'
title: Fsutil fsinfo execution
description: 'Adversaries may attempt to gather information about attached peripheral
devices and components connected to a computer system. Peripheral devices could
include auxiliary resources that support a variety of functionalities such as keyboards,
printers, cameras, smart card readers, or removable storage. This use case looks
for when fsutil is executed with fsinfo. - Threat Actor Association: APT29/Nobelium/Cozy
Bear - Software Association: Alphv/BlackCat'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) "fsutil" TERM(fsinfo) | table _time, host, user
process, process_*, signature_id, parent_* | bin span=1s | stats values(*) as *
by _time, host '
techniques:
- discovery:peripheral device discovery
technique_id:
- T1120
data_category:
- Windows event logs
- Process command-line parameters
references:
- https://www.welivesecurity.com/wp-content/uploads/2020/05/ESET_Turla_ComRAT.pdf
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) "fsutil" TERM(fsinfo)
Stage 2: table
| table _time, host, user process, process_*, signature_id, parent_*
Stage 3: bucket
| bin span=1s
Stage 4: 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 |
|
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<" |
| 1 | "fsutil" |
| 1 | TERM |
| 1 | fsinfo |