FINDING · EVALUATION
Adding nine beacon descriptors (inter-arrival-time moments, FFT peak period and power, flow count per endpoint triple, idle ratio) to the flow-statistics view improves Random Forest F1 from 0.747 to 0.856 (+0.109) — one order of magnitude larger than any multi-view fusion gain (+0.022). However, the top-weighted feature beacon_n_flows correlates with capture length (Spearman ρ = 0.718) and its single-feature ROC-AUC varies from 0.173 to 0.977 across folds, indicating it partly reflects a collection artifact rather than real beacon periodicity.
From 2026-nguyen-huu-multi-view-fusion-encrypted — Multi-View Fusion for Encrypted C2 Detection: A Leakage-Controlled Measurement Study of Evaluation Pitfalls · §V-C · 2026 · arXiv preprint
Implications
- Periodic callback timing regularity (beacon interval, FFT periodicity) is the single highest-value ML detection signal for encrypted C2 — circumvention transports using any form of periodic heartbeat or polling must randomize callback timing with substantial jitter to defeat this feature class.
- Limiting the number of flows per server address or multiplexing within a single long-lived connection reduces the flow-count-per-destination signal that functions as a strong detection artifact in grouped traffic analysis.
Tags
Extracted by claude-sonnet-4-6 — review before relying.