tool

Ruler S0358

Type: tool
Platforms: Windows, Office Suite
Created: 4 February 2019
Last modified: 25 April 2025

Ruler is a tool to abuse Microsoft Exchange services. It is publicly available on GitHub and the tool is executed via the command line. The creators of Ruler have also released a defensive tool, NotRuler, to detect its usage.[1][2]

TechniquesBottom 17%

TacticsBottom 12%

Threat groupunranked

CampaignsNone recorded

Enterprise ATT&CK only. Any Mobile or ICS rows on the same ATT&CK page are not carried.

Ruler MITRE reference S0358

Email Account T1087.003 ↗

Ruler can be used to enumerate Exchange users and dump the GAL.3

Discoveryno detection rules

Outlook Forms T1137.003 ↗

Ruler can be used to automate the abuse of Outlook Forms to establish persistence.4

Persistence1 detection rules

Outlook Home Page T1137.004 ↗

Ruler can be used to automate the abuse of Outlook Home Pages to establish persistence.5

Persistenceno detection rules

Outlook Rules T1137.005 ↗

Ruler can be used to automate the abuse of Outlook Rules to establish persistence.6

Persistenceno detection rules

Standing S0358

Reach is how much of ATT&CK this tool touches. Coverage is how well defended each thing it does is, as a median per technique rather than a total — a total would just restate the reach. Each figure is ranked against all 825 ATT&CK software entries only where that population actually spreads. Where most of the population shares one value, a percentile would rank the tie instead of the entity, so the raw value is shown and no rank is claimed.

Reach

Techniques4Bottom 17%

17th percentile · 83% of 825 ATT&CK software entries have more Enterprise techniques.

Tactics2Bottom 12%

12th percentile · 88% of 825 ATT&CK software entries have more tactics spanned.

Threat group161% tie · 22 values

61% of the population shares a single value across only 22 distinct values, so a percentile here would rank the tie, not the entity.

Campaigns085% tie · 8 values

85% of the population shares a single value across only 8 distinct values, so a percentile here would rank the tie, not the entity.

Coverage

Rules / technique0medBottom 1%

1st percentile · 99% of 825 ATT&CK software entries have more detection rules per technique.

Tests / technique0.5medBottom 3%

3rd percentile · 97% of 825 ATT&CK software entries have more atomic tests per technique.

Data comps / technique4med54% tie · 11 values

54% of the population shares a single value across only 11 distinct values, so a percentile here would rank the tie, not the entity.

Mitigations / technique2medTop 9%

91st percentile · 91% of 825 ATT&CK software entries have this many mitigations per technique or fewer.

5 of 8 axes carry an honest rank on this page. Coverage medians are taken across this tool’s 4 Enterprise techniques.

Range

Technique Campaign use over its cumulative rule count.

Campaigns · 0Sigma rules (cumulative) · 1Splunk ESCU (cumulative) · 0

Standing S0358

Select	Title	Description	Category	Status	Event	OS	Product	MITRE ATT&CK	CVEs	Severity	Author	Created	Updated	ID	Refs
		Detects the creation of a new Outlook form which can contain malicious code	Generic	test	file_event	windows	Sysmon	Persistence Office Application Startup Outlook Forms	-	high	Tobias Michalski (Nextron Systems)	2021-06-10	2023-02-22	c3edc6a5-d9d4-48d8-930e-aab518390917

Title

Description

Ruler S0358

Ruler MITRE reference S0358

Standing S0358

Reach

Coverage

Ruler MITRE reference S0358

Standing S0358

Reach

Coverage

Ruler detections S0358

Ruler detections S0358