| ID | Name |
|---|---|
| T1481.001 | Dead Drop Resolver |
| T1481.002 | Bidirectional Communication |
| T1481.003 | One-Way Communication |
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. This is 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, or enable operational resiliency (since this infrastructure may be dynamically changed).
| ID | Name | Description |
|---|---|---|
| S0310 | ANDROIDOS_ANSERVER.A |
ANDROIDOS_ANSERVER.A uses encrypted content within a blog site for part of its command and control. Specifically, the encrypted content contains URLs for other servers to be used for other aspects of command and control.[1] |
| S0422 | Anubis |
Anubis can retrieve the C2 address from Twitter and Telegram.[2][3] |
| S0539 | Red Alert 2.0 |
Red Alert 2.0 can fetch a backup C2 domain from Twitter if the primary C2 is unresponsive.[4] |
| S0318 | XLoader for Android |
XLoader for Android has fetched its C2 address from encoded Twitter names, as well as Instagram and Tumblr.[5] |
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
| ID | Data Source | Data Component | Detects |
|---|---|---|---|
| DS0041 | Application Vetting | Network Communication |
Application vetting services may provide a list of connections made or received by an application, or a list of domains contacted by the application. |
| DS0029 | Network Traffic | Network Connection Creation |
Many properly configured firewalls may naturally block command and control traffic. |