Skip to content

T1588.004 Digital Certificates

Adversaries may buy and/or steal 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.

Adversaries may purchase or steal SSL/TLS certificates to further their operations, such as encrypting C2 traffic (ex: Asymmetric Cryptography with Web Protocols) or even enabling Adversary-in-the-Middle if the certificate is trusted or otherwise added to the root of trust (i.e. Install Root Certificate). The purchase of digital 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 certificate materials directly from a compromised third-party, including from certificate authorities.1 Adversaries may register or hijack domains that they will later purchase an SSL/TLS certificate for.

Certificate authorities exist that allow adversaries to acquire SSL/TLS certificates, such as domain validation certificates, for free.4

After obtaining a digital certificate, an adversary may then install that certificate (see Install Digital Certificate) on infrastructure under their control.

Item Value
ID T1588.004
Sub-techniques T1588.001, T1588.002, T1588.003, T1588.004, T1588.005, T1588.006, T1588.007
Tactics TA0042
Platforms PRE
Version 1.2
Created 01 October 2020
Last Modified 24 October 2025

Procedure Examples

ID Name Description
G0098 BlackTech BlackTech has used valid, stolen digital certificates for some of their malware and tools.14
C0043 Indian Critical Infrastructure Intrusions Indian Critical Infrastructure Intrusions included the use of digital certificates spoofing Microsoft.15
G0032 Lazarus Group Lazarus Group has obtained SSL certificates for their C2 domains.7
G1014 LuminousMoth LuminousMoth has used a valid digital certificate for some of their malware.13
G0129 Mustang Panda Mustang Panda has obtained SSL certificates for their C2 domains.1011
C0006 Operation Honeybee For Operation Honeybee, the threat actors stole a digital signature from Adobe Systems to use with their MaoCheng dropper.16
C0047 RedDelta Modified PlugX Infection Chain Operations Mustang Panda acquired Cloudflare Origin CA TLS certificates during RedDelta Modified PlugX Infection Chain Operations.17
G1041 Sea Turtle Sea Turtle created new certificates using a technique called the actors performed “certificate impersonation,” a technique in which Sea Turtle obtained a certificate authority-signed X.509 certificate from another provider for the same domain imitating the one already used by the targeted organization.89
G0122 Silent Librarian Silent Librarian has obtained free Let’s Encrypt SSL certificates for use on their phishing pages.56
G1048 UNC3886 UNC3886 has deployed malware using the victim’s legitimate TLS certificate obtained from a compromised FortiGate device.12

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.

References

  1. Fisher, D. (2012, October 31). Final Report on DigiNotar Hack Shows Total Compromise of CA Servers. Retrieved March 6, 2017. ↩

  2. Insikt Group. (2019, June 18). A Multi-Method Approach to Identifying Rogue Cobalt Strike Servers. Retrieved September 16, 2024. ↩

  3. Kovar, R. (2017, December 11). Tall Tales of Hunting with TLS/SSL Certificates. Retrieved October 16, 2020. ↩

  4. Let’s Encrypt. (2020, April 23). Let’s Encrypt FAQ. Retrieved October 15, 2020. ↩

  5. Hassold, Crane. (2018, March 26). Silent Librarian: More to the Story of the Iranian Mabna Institute Indictment. Retrieved February 3, 2021. ↩

  6. Counter Threat Unit Research Team. (2019, September 11). COBALT DICKENS Goes Back to School…Again. Retrieved February 3, 2021. ↩

  7. Cybersecurity and Infrastructure Security Agency. (2021, February 21). AppleJeus: Analysis of North Korea’s Cryptocurrency Malware. Retrieved March 1, 2021. ↩

  8. Cisco Talos. (2019, April 17). Sea Turtle: DNS Hijacking Abuses Trust In Core Internet Service. Retrieved November 20, 2024. ↩

  9. Paul Rascagneres. (2019, July 9). Sea Turtle keeps on swimming, finds new victims, DNS hijacking techniques. Retrieved November 20, 2024. ↩

  10. EclecticIQ Threat Research Team. (2023, February 2). Mustang Panda APT Group Uses European Commission-Themed Lure to Deliver PlugX Malware. Retrieved September 9, 2025. ↩

  11. Patrick Whitsell. (2025, August 25). Deception in Depth: PRC-Nexus Espionage Campaign Hijacks Web Traffic to Target Diplomats. Retrieved September 9, 2025. ↩

  12. Punsaen Boonyakarn, Shawn Chew, Logeswaran Nadarajan, Mathew Potaczek, Jakub Jozwiak, and Alex Marvi. (2024, June 18). Cloaked and Covert: Uncovering UNC3886 Espionage Operations. Retrieved September 24, 2024. ↩

  13. Lechtik, M, and etl. (2021, July 14). LuminousMoth APT: Sweeping attacks for the chosen few. Retrieved October 20, 2022. ↩

  14. Cherepanov, A.. (2018, July 9). Certificates stolen from Taiwanese tech‑companies misused in Plead malware campaign. Retrieved May 6, 2020. ↩

  15. Recorded Future Insikt Group. (2022, April 6). Continued Targeting of Indian Power Grid Assets by Chinese State-Sponsored Activity Group. Retrieved November 21, 2024. ↩

  16. Sherstobitoff, R. (2018, March 02). McAfee Uncovers Operation Honeybee, a Malicious Document Campaign Targeting Humanitarian Aid Groups. Retrieved May 16, 2018. ↩

  17. Insikt Group. (2025, January 9). Chinese State-Sponsored RedDelta Targeted Taiwan, Mongolia, and Southeast Asia with Adapted PlugX Infection Chain. Retrieved January 14, 2025. ↩