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:Asymmetric Cryptography withWeb Protocols) or even enablingAdversary-in-the-Middle if added to the root of trust (i.e.Install Root Certificate).
After creating a digital certificate, an adversary may then install that certificate (seeInstall Digital Certificate) on infrastructure under their control.
| ID | Name | Description |
|---|---|---|
| G0016 | APT29 | APT29 has created self-signed digital certificates to enable mutual TLS authentication for malware.[1][2] |
| C0046 | ArcaneDoor | ArcaneDoor included acquiring digital certificates mimicking patterns associated with Cisco ASA appliances for command and control infrastructure.[3] |
| C0011 | C0011 | ForC0011,Transparent Tribe established SSL certificates on the typo-squatted domains the group registered.[4] |
| G0047 | Gamaredon Group | Gamaredon Group has used the same TLS certificate across its infrastructure.[5] |
| C0050 | J-magic Campaign | During theJ-magic Campaign, threat actors used self-signed certificates on VPS C2 infrastructure.[6] |
| G0056 | PROMETHIUM | PROMETHIUM has created self-signed digital certificates for use in HTTPS C2 traffic.[7] |
| G1053 | Storm-0501 | Storm-0501 has utilized their own self-signed TLS certificate "Microsoft IT TLS CA 5" with their infrastructure.[8] |
| 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. |
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0844 | Detection of Digital Certificates | AN1976 | 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.[9] |