Code Signing

Enforce binary and application integrity with digital signature verification to prevent untrusted code from executing.

ID: M1045
Version: 1.1
Created: 11 June 2019
Last Modified: 20 May 2020

Techniques Addressed by Mitigation

Domain ID Name Use
Enterprise T1059 Command and Scripting Interpreter

Where possible, only permit execution of signed scripts.

.001 PowerShell

Set PowerShell execution policy to execute only signed scripts.

.002 AppleScript

Require that all AppleScript be signed by a trusted developer ID before being executed - this will prevent random AppleScript code from executing.[1] This subjects AppleScript code to the same scrutiny as other .app files passing through Gatekeeper.

Enterprise T1554 Compromise Client Software Binary

Ensure all application component binaries are signed by the correct application developers.

Enterprise T1543 Create or Modify System Process

Enforce registration and execution of only legitimately signed service drivers where possible.

.003 Windows Service

Enforce registration and execution of only legitimately signed service drivers where possible.

Enterprise T1546 .006 Event Triggered Execution: LC_LOAD_DYLIB Addition

Enforce that all binaries be signed by the correct Apple Developer IDs.

.013 Event Triggered Execution: PowerShell Profile

Enforce execution of only signed PowerShell scripts. Sign profiles to avoid them from being modified.

Enterprise T1525 Implant Internal Image

Several cloud service providers support content trust models that require container images be signed by trusted sources.[2][3]

Enterprise T1036 Masquerading

Require signed binaries.

.001 Invalid Code Signature

Require signed binaries.

.005 Match Legitimate Name or Location

Require signed binaries and images.

Enterprise T1601 Modify System Image

Many vendors provide digitally signed operating system images to validate the integrity of the software used on their platform. Make use of this feature where possible in order to prevent and/or detect attempts by adversaries to compromise the system image. [4]

.001 Patch System Image

Many vendors provide digitally signed operating system images to validate the integrity of the software used on their platform. Make use of this feature where possible in order to prevent and/or detect attempts by adversaries to compromise the system image. [4]

.002 Downgrade System Image

Many vendors provide digitally signed operating system images to validate the integrity of the software used on their platform. Make use of this feature where possible in order to prevent and/or detect attempts by adversaries to compromise the system image. [4]

Enterprise T1505 Server Software Component

Ensure all application component binaries are signed by the correct application developers.

.001 SQL Stored Procedures

Ensure all application component binaries are signed by the correct application developers.

.002 Transport Agent

Ensure all application component binaries are signed by the correct application developers.

.004 IIS Components

Ensure IIS DLLs and binaries are signed by the correct application developers.

Enterprise T1204 .003 User Execution: Malicious Image

Utilize a trust model such as Docker Content Trust with digital signatures to ensure runtime verification of the integrity and publisher of specific image tags.[3][2]

References