Adversaries may exfiltrate data to a cloud storage service rather than over their primary command and control channel. Cloud storage services allow for the storage, edit, and retrieval of data from a remote cloud storage server over the Internet.
Examples of cloud storage services include Dropbox and Google Docs. Exfiltration to these cloud storage services can provide a significant amount of cover to the adversary if hosts within the network are already communicating with the service.
|M1021||Restrict Web-Based Content||
Web proxies can be used to enforce an external network communication policy that prevents use of unauthorized external services.
|ID||Data Source||Data Component|
|DS0029||Network Traffic||Network Traffic Content|
|Network Traffic Flow|
Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server) to known cloud storage services. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. User behavior monitoring may help to detect abnormal patterns of activity.