T1137 Office Application Startup

T1137 Office Application Startup

High-Level Description

Adversaries may leverage Microsoft Office-based applications for persistence between startups. Microsoft Office is a fairly common application suite on Windows-based operating systems within an enterprise network. There are multiple mechanisms that can be used with Office for persistence when an Office-based application is started; this can include the use of Office Template Macros and add-ins.

A variety of features have been discovered in Outlook that can be abused to obtain persistence, such as Outlook rules, forms, and Home Page. These persistence mechanisms can work within Outlook or be used through Office 365.

Kill Chain Phase

• Persistence (TA0003)

Platforms: Windows, Office Suite

What to Check

• Identify if Office Application Startup technique is applicable to target environment
• Check Windows systems for indicators of Office Application Startup
• Check Office Suite systems for indicators of Office Application Startup
• Verify mitigations are bypassed or absent (4 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: Office Application Startup - Outlook as a C2

As outlined in MDSEC's Blog post https://www.mdsec.co.uk/2020/11/a-fresh-outlook-on-mail-based-persistence/ it is possible to use Outlook Macro as a way to achieve persistance and execute arbitrary commands. This transform Outlook into a C2. Too achieve this two things must happened on the syste

• The macro security registry value must be set to '1'
• A file called VbaProject.OTM must be created in the Outlook Folder.

Supported Platforms: windows