Computer Discovery And Export Via Get-ADComputer Cmdlet

Severity: medium
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects usage of the Get-ADComputer cmdlet to collect computer information and output it to a file

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1033` System Owner/User Discovery

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
OriginalFileName: PowerShell.EXE
OriginalFileName: pwsh.dll

Stage 2: `all of selection_cli`

or:
CommandLine|contains: ' > '
CommandLine|contains: ' | Select '
CommandLine|contains: Add-Content
CommandLine|contains: Out-File
CommandLine|contains: Set-Content
CommandLine|contains: ' -Filter \*'
CommandLine|contains: 'Get-ADComputer '

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
`CommandLine`	match	`-Filter \*` corpus 2 (sigma 2) `>` corpus 5 (sigma 5) `\| Select` corpus 2 (sigma 2) `Add-Content` corpus 2 (sigma 2) `Get-ADComputer` `Out-File` corpus 3 (sigma 3) `Set-Content` corpus 2 (sigma 2)
`Image`	ends_with	`\powershell.exe` corpus 143 (sigma 143) `\pwsh.exe` corpus 140 (sigma 140)
`OriginalFileName`	eq	`PowerShell.EXE` corpus 64 (sigma 60, splunk 4) `pwsh.dll` corpus 72 (sigma 68, splunk 4)