Suspicious MSDT Parent Process

Severity: high
Author: Nextron Systems
Source: upstream

Detects msdt.exe executed by a suspicious parent as seen in CVE-2022-30190 / Follina exploitation

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1036` Masquerading, `T1218` System Binary Proxy Execution

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_parent`

or:
ParentImage|endswith: '\cmd.exe'
ParentImage|endswith: '\cscript.exe'
ParentImage|endswith: '\mshta.exe'
ParentImage|endswith: '\powershell.exe'
ParentImage|endswith: '\pwsh.exe'
ParentImage|endswith: '\regsvr32.exe'
ParentImage|endswith: '\rundll32.exe'
ParentImage|endswith: '\schtasks.exe'
ParentImage|endswith: '\wmic.exe'
ParentImage|endswith: '\wscript.exe'
ParentImage|endswith: '\wsl.exe'

Stage 2: `all of selection_msdt`

or:
Image|endswith: '\msdt.exe'
OriginalFileName: msdt.exe

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	`\msdt.exe` corpus 10 (sigma 10)
`OriginalFileName`	eq	`msdt.exe` corpus 6 (sigma 6)
`ParentImage`	ends_with	`\cmd.exe` corpus 13 (sigma 13) `\cscript.exe` corpus 14 (sigma 14) `\mshta.exe` corpus 10 (sigma 10) `\powershell.exe` corpus 16 (sigma 16) `\pwsh.exe` corpus 16 (sigma 16) `\regsvr32.exe` corpus 11 (sigma 11) `\rundll32.exe` corpus 12 (sigma 12) `\schtasks.exe` `\wmic.exe` `\wscript.exe` corpus 14 (sigma 14) `\wsl.exe` corpus 4 (sigma 4)