Yellow Cockatoo Powershell Startup Folder Persistence (RedCanary Threat Detection Report)

SIGMA detection rule by RedCanary, Sigma formatting by Micah Babinski · GPL-3.0

Detects .lnk files created by Powershell in the startup folder. Associated with (but not unique to) Yellow Cockatoo, AKA Solarmarker/Jupyter Stealer. Part of the RedCanary 2023 Threat Detection Report.

title: Yellow Cockatoo Powershell Startup Folder Persistence (RedCanary Threat Detection Report)
id: 874acb07-02f7-4c9f-8069-e0659c6d3fad
status: experimental
description: |
    Detects .lnk files created by Powershell in the startup folder. Associated with (but not unique to)
    Yellow Cockatoo, AKA Solarmarker/Jupyter Stealer. Part of the RedCanary 2023 Threat Detection Report.
references:
    - https://redcanary.com/threat-detection-report/threats/yellow-cockatoo/
author: RedCanary, Sigma formatting by Micah Babinski
date: 2023/05/10
tags:
    - attack.initial_access
    - attack.defense_evasion
    - attack.t1566
logsource:
    category: file_event
    product: windows
detection:
    selection_img:
        Image|endswith: '\powershell.exe'
    selection_filepath:
        TargetFilename|contains: 'start menu\programs\startup'
    selection_file_ext:
        TargetFilename|endswith: '.lnk'
    condition: all of selection*
falsepositives:
    - Unknown
level: low

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

2b879930-6eee-4890-924d-3512780d6f24

Propose edits, view related rules, and engage with the community through comments.

Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

Community Discussion