Ruler

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]

ID: S0358
Type: TOOL
Platforms: Windows, Office 365
Version: 1.1
Created: 04 February 2019
Last Modified: 22 June 2020

Techniques Used

Domain ID Name Use
Enterprise T1087 .003 Account Discovery: Email Account

Ruler can be used to enumerate Exchange users and dump the GAL.[1]

Enterprise T1137 .004 Office Application Startup: Outlook Home Page

Ruler can be used to automate the abuse of Outlook Home Pages to establish persistence.[1]

.005 Office Application Startup: Outlook Rules

Ruler can be used to automate the abuse of Outlook Rules to establish persistence.[1]

.003 Office Application Startup: Outlook Forms

Ruler can be used to automate the abuse of Outlook Forms to establish persistence.[1]

Groups That Use This Software

ID Name References
G0064 APT33

[3][4]

References