Encrypted Channel

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.

ID: T1521
Sub-techniques:  T1521.001, T1521.002, T1521.003
Tactic Type: Post-Adversary Device Access
Platforms: Android, iOS
Version: 2.0
Created: 01 October 2019
Last Modified: 24 October 2025

Procedure Examples

ID Name Description
S1095 AhRat

AhRat can communicate with the C2 using HTTPS requests.[1]

S0302 Twitoor

Twitoor encrypts its C2 communication.[2]

Mitigations

This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.

Detection Strategy

ID Name Analytic ID Analytic Description
DET0641 Detection of Encrypted Channel AN1716

Since data encryption is a common practice in many legitimate applications and uses standard programming language-specific APIs, encrypting data for command and control communication is regarded as undetectable to the user.

AN1717

Since data encryption is a common practice in many legitimate applications and uses standard programming language-specific APIs, encrypting data for command and control communication is regarded as undetectable to the user.

References