Enable Microsoft Dynamic Data Exchange

Severity: medium
Author: frack113
Source: upstream

Enable Dynamic Data Exchange protocol (DDE) in all supported editions of Microsoft Word or Excel.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1559.002` Inter-Process Communication: Dynamic Data Exchange

Event coverage

Provider	Event ID	Title
Sysmon	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `1 of selection_word`

Details: ['DWORD (0x00000001)', 'DWORD (0x00000002)']
TargetObject|endswith: '\Word\Security\AllowDDE'

Stage 2: `1 of selection_excel`

or:
TargetObject|endswith: '\Excel\Security\DisableDDEServerLaunch'
TargetObject|endswith: '\Excel\Security\DisableDDEServerLookup'
Details: 'DWORD (0x00000000)'

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
`Details`	eq	`DWORD (0x00000000)` corpus 38 (sigma 38) `DWORD (0x00000001)` corpus 37 (sigma 37) `DWORD (0x00000002)` corpus 9 (sigma 9)
`TargetObject`	ends_with	`\Excel\Security\DisableDDEServerLaunch` `\Excel\Security\DisableDDEServerLookup` `\Word\Security\AllowDDE`