Dead Drop Resolver
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers. Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection. Use of a dead drop resolver may also protect back-end C2 infrastructure from discovery through malware binary analysis while also enabling operational resiliency (since this infrastructure may be dynamically changed).
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN0158
Detection of a process or script that accesses a common web service to retrieve content containing obfuscated indicators of a secondary C2 server (dead drop resolver behavior).
- AN0159
Detection of a process or script that accesses a common web service to retrieve content containing obfuscated indicators of a secondary C2 server (dead drop resolver behavior).
- AN0160
Detection of a process or script that accesses a common web service to retrieve content containing obfuscated indicators of a secondary C2 server (dead drop resolver behavior).
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.