Potential Excel.EXE DCOM Lateral Movement Via ActivateMicrosoftApp

Severity: high
Author: Aaron Stratton
Source: upstream

Detects suspicious child processes of Excel which could be an indicator of lateral movement leveraging the "ActivateMicrosoftApp" Excel DCOM object.

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

Stages and Predicates

Stage 1: `all of selection_parent`

ParentImage|endswith: '\excel.exe'

Stage 2: `all of selection_child`

or:
Image|endswith: '\foxprow.exe'
Image|endswith: '\schdplus.exe'
Image|endswith: '\winproj.exe'
OriginalFileName: foxprow.exe
OriginalFileName: schdplus.exe
OriginalFileName: winproj.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	`\foxprow.exe` `\schdplus.exe` `\winproj.exe`
`OriginalFileName`	eq	`foxprow.exe` `schdplus.exe` `winproj.exe`
`ParentImage`	ends_with	`\excel.exe` corpus 2 (sigma 2)