FedScope--Federated Host Embeddings From Telescope Traffic: Design and Implementation

A network telescope is a range of IP addresses that host no services. Millions of bots and scanners contact it to look for vulnerable systems, and the traffic it exposes is fundamental to understanding malicious activities. The visibility a telescope offers depends on its size and geolocation, and merging the information from multiple telescopes could help increase visibility and uncover more malicious activities. However, sharing raw telescope data is complicated, calling for solutions that allow one to directly share the knowledge rather than the data obtained from multiple deployments. In this paper, we explore the application of Federated Learning (FL) to create and share such global knowledge from the malicious activities seen in distributed telescopes. For that, we introduce FedScope, an FL-based solution for generating host embeddings in a distributed way. We compare FedScope to local and distributed alternatives in downstream tasks, such as sender classification or coordinated activities detection. We show that FedScope 1) produces embeddings of equal or higher quality than those of a single telescope; 2) increases coverage, allowing the global model to monitor more malicious actors; 3) avoids the sharing of the raw data, limiting exchanged data.