Custom File Open Handler Executes PowerShell

Status: test
Severity: high
Log source: category registry_set, product windows
Author: CD_R0M_
Source: github.com/SigmaHQ/sigma

Detects the abuse of custom file open handler, executing powershell

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1202` Indirect Command Execution

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 13: RegistryEvent (Value Set)

Rule body

title: Custom File Open Handler Executes PowerShell
id: 7530b96f-ad8e-431d-a04d-ac85cc461fdc
status: test
description: Detects the abuse of custom file open handler, executing powershell
references:
    - https://news.sophos.com/en-us/2022/02/01/solarmarker-campaign-used-novel-registry-changes-to-establish-persistence/?cmp=30728
author: CD_R0M_
date: 2022-06-11
modified: 2023-08-17
tags:
    - attack.stealth
    - attack.t1202
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: 'shell\open\command\'
        Details|contains|all:
            - 'powershell'
            - '-command'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    TargetObject|contains: 'shell\open\command\'
    Details|contains|all:
        - 'powershell'
        - '-command'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Details`	match	`-command` `powershell` corpus 11 (sigma 9, elastic 1, chronicle 1)	`field:"Details" kind:match`
`TargetObject`	match	`shell\open\command\`	`field:"TargetObject" kind:match value:"shell\open\command\"`

Custom File Open Handler Executes PowerShell

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`