Detection rules › Splunk
Startup Folder Location Modified - Windows (PowerShell)
Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. Adversaries may modify registry values to point to a new startup folder where a payload could be stored to launch at boot. This use case detects modifications to registry values that can be used to change the startup folder location
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
| Privilege Escalation | T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
References
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1547.001/T1547.001.md#atomic-test-10---change-startup-folder---hklm-modify-user-shell-folders-common-startup-value
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1547.001/T1547.001.md#atomic-test-11---change-startup-folder---hkcu-modify-user-shell-folders-startup-value
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body yaml
id: '19911.35071'
title: Startup Folder Location Modified - Windows
description: 'Adversaries may achieve persistence by adding a program to a startup
folder or referencing it with a Registry run key. Adding an entry to the "run keys"
in the Registry or startup folder will cause the program referenced to be executed
when a user logs in. Adversaries may modify registry values to point to a new startup
folder where a payload could be stored to launch at boot. This use case detects
modifications to registry values that can be used to change the startup folder location.
Atomics T1546.002 Test #10 Atomics T1546.002 Test #11'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
"<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") ((TERM(Set-ItemProperty)
OR TERM(sp) OR (TERM(reg) TERM(add)))) "Startup" "Windows\\CurrentVersion\\Explorer\\User
Shell Folders" | table _time, host, user, parent_process*, process, process_*, signature_id,
user_id | bin span=1s | stats values(*) as * by _time, host '
techniques:
- persistence:boot or logon autostart execution:registry run keys / startup folder
- privilege-escalation:boot or logon autostart execution:registry run keys / startup
folder
technique_id:
- T1547.001
data_category:
- PowerShell logs
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1547.001/T1547.001.md#atomic-test-10---change-startup-folder---hklm-modify-user-shell-folders-common-startup-value
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1547.001/T1547.001.md#atomic-test-11---change-startup-folder---hkcu-modify-user-shell-folders-startup-value
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<") ((TERM(Set-ItemProperty) OR TERM(sp) OR (TERM(reg) TERM(add)))) "Startup" "Windows\\CurrentVersion\\Explorer\\User Shell Folders"
Stage 2: table
| table _time, host, user, parent_process*, process, process_*, signature_id, user_id
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>4103<" |
| 1 | TERM |
| 1 | "<EventID>4104<" |
| 1 | "Set-ItemProperty" |
| 1 | TERM |
| 1 | sp |
| 1 | TERM |
| 1 | reg |
| 1 | TERM |
| 1 | add |
| 1 | "Startup" |
| 1 | "Windows\\CurrentVersion\\Explorer\\User Shell Folders" |