SigmaHQ/rules/windows/powershell/powershell_shellcode_b64.yml

title: PowerShell ShellCode
id: 16b37b70-6fcf-4814-a092-c36bd3aafcbd
status: experimental
description: Detects Base64 encoded Shellcode
references:
    - https://twitter.com/cyb3rops/status/1063072865992523776
tags:
    - attack.defense_evasion
    - attack.privilege_escalation
    - attack.t1055
    - attack.execution
    - attack.t1059.001
    - attack.t1086  #an old one
author: David Ledbetter (shellcode), Florian Roth (rule)
date: 2018/11/17
modified: 2020/12/01
logsource:
    product: windows
    service: powershell
    definition: 'Script block logging must be enabled'
detection:
    selection:
        EventID: 4104
        ScriptBlockText|contains: 'AAAAYInlM'
    selection2:
        ScriptBlockText|contains:
            - 'OiCAAAAYInlM'
            - 'OiJAAAAYInlM'
    condition: selection and selection2
falsepositives:
    - Unknown
level: critical
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`title: PowerShell ShellCode`
Added UUIDs to rules 2019-11-12 22:12:27 +00:00			`id: 16b37b70-6fcf-4814-a092-c36bd3aafcbd`
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`status: experimental`
			`description: Detects Base64 encoded Shellcode`
			`references:`
			`- https://twitter.com/cyb3rops/status/1063072865992523776`
			`tags:`
windows/powershell folder reviewed. Old ID’s marked with comment “an old one”. These ID’s have to be removed in future. 2020-08-24 00:01:50 +00:00			`- attack.defense_evasion`
Added missing tags and some minor improvements 2019-03-05 22:25:49 +00:00			`- attack.privilege_escalation`
			`- attack.t1055`
windows/powershell folder reviewed. Old ID’s marked with comment “an old one”. These ID’s have to be removed in future. 2020-08-24 00:01:50 +00:00			`- attack.execution`
			`- attack.t1059.001`
			`- attack.t1086 #an old one`
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`author: David Ledbetter (shellcode), Florian Roth (rule)`
			`date: 2018/11/17`
Update powershell_shellcode_b64.yml 2020-12-01 01:24:35 +00:00			`modified: 2020/12/01`
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`logsource:`
			`product: windows`
			`service: powershell`
Update powershell_shellcode_b64.yml logsource to use the correct Sigma schema values 2020-07-12 02:17:06 +00:00			`definition: 'Script block logging must be enabled'`
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`detection:`
			`selection:`
			`EventID: 4104`
Update powershell_shellcode_b64.yml 2020-12-01 01:24:35 +00:00			`ScriptBlockText\|contains: 'AAAAYInlM'`
			`selection2:`
Fixes 2021-04-03 21:21:13 +00:00			`ScriptBlockText\|contains:`
Update powershell_shellcode_b64.yml 2020-12-01 01:24:35 +00:00			`- 'OiCAAAAYInlM'`
			`- 'OiJAAAAYInlM'`
			`condition: selection and selection2`
Rule: Detect base64 encoded PowerShell shellcode https://twitter.com/cyb3rops/status/1063072865992523776 2018-11-17 08:10:09 +00:00			`falsepositives:`
			`- Unknown`
			`level: critical`