MMC Spawning Windows Shell

Severity: high
Author: Karneades, Swisscom CSIRT
Source: upstream

Detects a Windows command line executable started from MMC

MITRE ATT&CK coverage

Tactic	Techniques
Lateral Movement	`T1021.003` Remote Services: Distributed Component Object Model

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `all of selection1`

ParentImage|endswith: '\mmc.exe'

Stage 2: `all of selection2`

or:
Image|endswith: '\bash.exe'
Image|endswith: '\cmd.exe'
Image|endswith: '\cscript.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\reg.exe'
Image|endswith: '\regsvr32.exe'
Image|endswith: '\sh.exe'
Image|endswith: '\wscript.exe'
Image|contains: '\BITSADMIN'

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
`Image`	ends_with	`\bash.exe` corpus 17 (sigma 17) `\cmd.exe` corpus 92 (sigma 92) `\cscript.exe` corpus 64 (sigma 64) `\powershell.exe` corpus 143 (sigma 143) `\pwsh.exe` corpus 140 (sigma 140) `\reg.exe` corpus 46 (sigma 46) `\regsvr32.exe` corpus 57 (sigma 57) `\sh.exe` corpus 13 (sigma 13) `\wscript.exe` corpus 64 (sigma 64)
`Image`	match	`\BITSADMIN`
`ParentImage`	ends_with	`\mmc.exe` corpus 3 (sigma 3)