Adversaries may compromise serverless cloud infrastructure, such as Cloudflare Workers, AWS Lambda functions, or Google Apps Scripts, that can be used during targeting. By utilizing serverless infrastructure, adversaries can make it more difficult to attribute infrastructure used during operations back to them.
Once compromised, the serverless runtime environment can be leveraged to either respond directly to infected machines or to Proxy traffic to an adversary-owned command and control server.(Citation: BlackWater Malware Cloudflare Workers)(Citation: AWS Lambda Redirector)(Citation: GWS Apps Script Abuse 2021) As traffic generated by these functions will appear to come from subdomains of common cloud providers, it may be difficult to distinguish from ordinary traffic to these providers - making it easier to Hide Infrastructure.(Citation: Detecting Command & Control in the Cloud)(Citation: BlackWater Malware Cloudflare Workers)
Detection of Serverless
Pre-compromise: Pre-compromise mitigations involve proactive measures and defenses implemented to prevent adversaries from successfully identifying and exploiting weaknesses during the Reconnaissance and Resource Development phases of an attack. These activities focus on reducing an organization's attack surface, identify adversarial preparation efforts, and increase the difficulty for attackers to conduct successful operations. This mitigation can be implemented through the following measures:
Limit Information Exposure:
Protect Domain and DNS Infrastructure:
External Monitoring:
Threat Intelligence:
Content and Email Protections:
Training and Awareness: