Obtain Capabilities: Code Signing Certificates

Adversaries may buy and/or steal code signing certificates that can be used during targeting. Code signing is the process of digitally signing executables and scripts to confirm the software author and guarantee that the code has not been altered or corrupted. Code signing provides a level of authenticity for a program from the developer and a guarantee that the program has not been tampered with.[1] Users and/or security tools may trust a signed piece of code more than an unsigned piece of code even if they don't know who issued the certificate or who the author is.

Prior to Code Signing, adversaries may purchase or steal code signing certificates for use in operations. The purchase of code signing certificates may be done using a front organization or using information stolen from a previously compromised entity that allows the adversary to validate to a certificate provider as that entity. Adversaries may also steal code signing materials directly from a compromised third-party.

ID: T1588.003
Sub-technique of:  T1588
Platforms: PRE
Version: 1.1
Created: 01 October 2020
Last Modified: 17 October 2021

Procedure Examples

ID Name Description
S0576 MegaCortex

MegaCortex has used code signing certificates issued to fake companies to bypass security controls.[2]

G0102 Wizard Spider

Wizard Spider obtained a code signing certificate signed by Digicert for some of its malware.[3]

Mitigations

ID Mitigation Description
M1056 Pre-compromise

This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.

Detection

ID Data Source Data Component
DS0004 Malware Repository Malware Metadata

Consider analyzing code signing certificates for features that may be associated with the adversary and/or their developers, such as the thumbprint, algorithm used, validity period, common name, and certificate authority. Malware repositories can also be used to identify additional samples associated with the adversary and identify patterns an adversary has used in procuring code signing certificates.

Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related follow-on behavior, such as Code Signing or Install Root Certificate.

References