Adversaries may explicitly employ a known encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Despite the use of a secure algorithm, these implementations may be vulnerable to reverse engineering if necessary secret keys are encoded and/or generated within malware samples/configuration files.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0641 | Detection of Encrypted Channel | AN1716 |
For Android, detect Encrypted Channel from documented management, network, or vetting evidence; treat state queries as periodic observations rather than real-time events. Correlate Application Permission via Android Enterprise DPC / Application Vetting [DevicePolicyManager.getPermissionGrantState(); PackageManager manifest/requested-permission review]; Application State via Android Enterprise / EMM [Managed package inventory/status and package metadata]; File Creation via Application Vetting / Forensic Acquisition [Dynamic filesystem trace or acquired app-container/filesystem artifacts: App writes high-entropy blob (Shannon entropy > $EntropyThreshold$) to local staging path immediately before outbound transmission — encrypted staging artifact confirms app-layer encryption occurred]. Alert on a sequence or state change inconsistent with the device/app baseline, approved management policy, or expected user workflow; do not infer unobserved API calls, file/process activity, or payload content from management state alone. |
| AN1717 |
Indirect evidence of application-layer encrypted channel usage inferred through anomalous background processing and network transmission patterns following application activity, where encryption operations are not directly observable. Detection correlates background execution + network behavior + application entitlement posture to identify misuse of encrypted communication channels. |