Web Service: One-Way Communication

Adversaries may use an existing, legitimate external Web service channel as a means for sending commands to a compromised system without receiving return output. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems may opt to send the output from those commands back over a different C2 channel, including to another distinct Web service. Alternatively, compromised systems may return no output at all in cases where adversaries want to send instructions to systems and do not want a response.

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.

ID: T1481.003
Sub-technique of:  T1481
Tactic Type: Post-Adversary Device Access
Platforms: Android, iOS
Version: 1.2
Created: 06 April 2022
Last Modified: 14 August 2023

Procedure Examples

ID Name Description
S0302 Twitoor

Twitoor can be controlled via Twitter.[1]

Mitigations

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

Detection

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 one-way command and control traffic.

References