T1048 Exfiltration Over Alternative Protocol

This control provides for monitoring, encrypting, and restricting communications between environments. Configuring access controls, network firewalls, and IP-based restrictions for accessing cloud resources helps mitigate the risk of alternative exfiltration through cloud services. Also, network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary command and control infrastructure and malware can be used to mitigate exfiltration activity at the network level.

This control provides for appropriately segmented and segregated cloud environments. Configuring access controls and network firewalls to enforce restrictions on accessing cloud resources, while allowing only essential ports and traffic, helps mitigate the risk of alternative exfiltration through cloud services.

This control provides for the implementation of defense-in-depth network security controls for securing the cloud environment. Configuring access controls and network firewalls to enforce restrictions on accessing cloud resources, while allowing only essential ports and traffic, helps mitigate the risk of alternative exfiltration through cloud services. Also, network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary command and control infrastructure and malware can be used to mitigate exfiltration activity at the network level.

This control describes the enforcement of the principle of least privilege implementing controls such as regular automated reviews of access permissions, enforcing MFA for high-risk accounts, promptly revoking unused privileges, and by limiting access to sensitive data. Adversaries has been observed using this technique to directly download cloud user data such as OneDrive files. For this technique, in terms of mitigation, Configure user permissions groups and roles for access to cloud storage. Implement strict Identity and Access Management (IAM) controls to prevent access to storage solutions except for the applications, users, and services that require access. Ensure that temporary access tokens are issued rather than permanent credentials, especially when access is being granted to entities outside of the internal security boundary.

This control describes how the CSP and CSC must independently implement technical safeguards such as network segmentation, encryption (at rest and in transit), secure key management, and access controls to prevent unauthorized replication or use of production data in non-production environments. For this technique, adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location, such as a non-production environment to facilitate exfiltration. In terms of mitigation, follow best practices for network firewall configurations to allow only necessary ports and traffic to enter and exit the network. Also, consider using IP allowlisting along with user account management to ensure that data access is restricted not only to valid users but only from expected IP ranges to mitigate the use of stolen or replication to access data.

The control describes the implementation of strong technical and procedural safeguards, such as TLS with strong keys)to protect sensitive data during transfer and prevent unauthorized access or interception. For this technique, adversaries may steal sensitive data by exfiltrating it over a different protocol than that of the existing command and control channel. In terms of mitigation, the use of IP allowlisting along with user account management to ensure that data access is restricted not only to valid users but only from expected IP ranges could mitigate the use of stolen credentials to access data.

This control requires the Cloud Service Provider (CSP) to implement robust mitigative controls such as network segmentation and firewalling, encryption, access controls with multi-factor authentication and intrusion detection to ensure sensitive customer data is protected throughout its lifecycle. As it related to this technique, many IaaS and SaaS platforms (such as Microsoft Exchange, Microsoft SharePoint, GitHub, and AWS S3) support the direct download of files, emails, source code, and other sensitive information via the web console or Cloud API. In terms of mitigation, configure network firewalls to allow only necessary ports and traffic to enter and exit the network, configure user permissions groups and roles for access to cloud storage, or enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network. Cloud service providers support IP-based restrictions when accessing cloud resources.

Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. This control requires implementing data leakage prevention (DLP) capapbiltities on endpoint devices. This includes classifying and inventorying data, protecting sensitive information in transit and at rest, monitoring for unauthorized disclosures, and responding to policy violations.

Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. This control enforces the classification of data by type, criticality, and sensitivity level to enable appropriate protections (including DLP measures), mitigating attacker techniques such as data exfiltration, unauthorized disclosure, and the misuse of unprotected sensitive information. Some DLP capabilities can detect and block sensitive data being uploaded via web browsers.