Develop Capabilities: Digital Certificates

Before compromising a victim, adversaries may create self-signed SSL/TLS certificates that can be used during targeting. SSL/TLS certificates are designed to instill trust. They include information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate with its owner. In the case of self-signing, digital certificates will lack the element of trust associated with the signature of a third-party certificate authority (CA).

Adversaries may create self-signed SSL/TLS certificates that can be used to further their operations, such as encrypting C2 traffic (ex: Web Protocols) or even enabling Man-in-the-Middle if added to the root of trust (i.e. Install Root Certificate).

ID: T1587.003
Sub-technique of:  T1587
Tactic: Resource Development
Platforms: PRE
Data Sources: SSL/TLS certificates
Version: 1.0
Created: 01 October 2020
Last Modified: 22 October 2020

Procedure Examples

Name Description
APT29

APT29 has created self-signed digital certificates to enable mutual TLS authentication for malware.[1][2]

PROMETHIUM

PROMETHIUM has created self-signed digital certificates for use in HTTPS C2 traffic.[3]

Mitigations

Mitigation Description
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

Consider use of services that may aid in the tracking of certificates in use on sites across the Internet. In some cases it may be possible to pivot on known pieces of certificate information to uncover other adversary infrastructure.[4]

Detection efforts may be focused on related behaviors, such as Web Protocols, Asymmetric Cryptography, and/or Install Root Certificate.

References