Detection rules › Splunk

PowerShell XML Retrieval (PowerShell)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

This use case detects PowerShell commands attempting to retrieve data from XML files via http or https

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '15890.23710'
title: PowerShell XML Retrieval
description: 'This use case detects PowerShell commands attempting to retrieve data
  from XML files via http or https. Atomics T1059.001 Test #7 Atomics T1059.001 Test
  #8'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
  "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") ("MsXml2.ServerXmlHttp"
  OR TERM(ComObject) OR "xml") | table _time, host, user process, process_*, signature_id
  | bin span=1s | stats values(*) as * by _time, host | where match(process, "(?i)http(s?):\/\/")
  and match (process, "(?i)xml") '
techniques:
- execution:command and scripting interpreter:powershell
- execution:command and scripting interpreter
technique_id:
- T1059.001
- T1059
data_category:
- PowerShell logs
- Process command-line parameters
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1059.001/T1059.001.md#atomic-test-7---powershell-msxml-com-object---with-prompt

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") ("MsXml2.ServerXmlHttp" OR TERM(ComObject) OR "xml")

Stage 2: table

| table _time, host, user process, process_*, signature_id

Stage 3: bucket

| bin span=1s

Stage 4: stats

| stats values(*) as * by _time, host

Stage 5: where

| where match(process, "(?i)http(s?):\/\/") and match (process, "(?i)xml")

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.

FieldKindValues
EventCodeeq
  • 4103 corpus 105 (splunk 105)
  • 4104 corpus 268 (splunk 268)
processmatch
  • "(?i)http(s?):\/\/" corpus 3 (splunk 3)
  • "(?i)xml" corpus 3 (splunk 3)

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.

StageTerm
1TERM
1"<EventID>4103<"
1TERM
1"<EventID>4104<"
1"MsXml2.ServerXmlHttp"
1TERM
1ComObject
1"xml"