Adversaries may use an existing, legitimate external Web service as a means for relaying data to/from a compromised system. Popular websites, cloud services, and social media acting as a mechanism for C2 may give a significant amount of cover 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, Microsoft, or Twitter, makes it easier for adversaries to hide in expected noise.(Citation: Broadcom BirdyClient Microsoft Graph API 2024) Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.
Use of Web services may also protect back-end C2 infrastructure from discovery through malware binary analysis while also enabling operational resiliency (since this infrastructure may be dynamically changed).
View in MITRE ATT&CK®Technique ID | Technique Name | Number of Mappings |
---|---|---|
T1102.003 | One-Way Communication | 2 |
T1102.002 | Bidirectional Communication | 2 |
T1102.001 | Dead Drop Resolver | 2 |