Kaleido: Network traffic attribution using multifaceted footprinting

Network traffic attribution, namely, inferring users responsible for activities observed on network interfaces, is one fundamental yet challenging task in network security forensics. Compared with other user-system interaction records, network traces are inherently coarsegrained, context-sensitive, and detached from user ends. This paper presents Kaleido, a new network traffic attribution tool with a series of key features: a) it adopts a new class of inductive discriminant models to capture user- and context-specific patterns ("footprints") from different aspects of network traffic; b) it applies efficient learning methods to extracting and aggregating such footprints from noisy historical traces; c) with the help of novel indexing structures, it is able to perform efficient, runtime traffic attribution over high-volume network traces. The efficacy of Kaleido is evaluated with extensive experimental studies using the real network traces collected over three months in a large enterprise network.