> For the complete documentation index, see [llms.txt](https://docs.fusion.vectra.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fusion.vectra.ai/detection-models/library/post-compromise/anomalous_traffic_s3.md). # anomalous\_traffic\_s3 Explanation This event is triggered by Netography's Fusion Portal when it detects a data transfer to Amazon S3 that exceeds an automatically determined baseline threshold. Auto Thresholding observes r **Explanation** This event is triggered by Netography's Fusion Portal when it detects a data transfer to Amazon S3 that exceeds an automatically determined baseline threshold. Auto Thresholding observes related network traffic to determine a baseline and then defines thresholds as a number of standard deviations from the typically observed traffic. This event specifically looks for data transfers to S3 that are multiple standard deviations greater than the learned baseline. **What to Look For** Anomalous traffic to S3 may be an indication that your network is compromised and attackers are stealing information by moving it (exfiltrating it) off your network. Attackers frequently exfiltrate data using S3 (Amazon Simple Storage Service) because it is a low-cost, highly available cloud storage service. Detections of anomalous traffic to S3 are worthy of investigation because they may be indicative of a ransomware attack or industrial espionage. Investigate hosts that are the source of this sort of activity in order to make sure that it is authorized and expected, and the hosts have not been compromised. Ensure that hosts sending data to Amazon S3 are authorized to send data into a public cloud and that they are storing data in an approved destination S3 bucket. Check network logs for additional information to ensure that sensitive information is secure. **Related MITRE ATT\&CK Categories** [Exfiltration - Enterprise](https://attack.mitre.org/tactics/TA0010/) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.fusion.vectra.ai/detection-models/library/post-compromise/anomalous_traffic_s3.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.