HoneyStat: Local Worm Detection Using Honeypots

Abstract

Worm detection systems have traditionally used global strategies and focused on scan rates. The noise associated with this approach requires statistical techniques and large data sets (e.g., 2²⁰ monitored machines) to yield timely alerts and avoid false positives. Worm detection techniques for smaller local networks have not been fully explored.

We consider how local networks can provide early detection and compliment global monitoring strategies. We describe HoneyStat, which uses modified honeypots to generate a highly accurate alert stream with low false positive rates. Unlike traditional highly-interactive honeypots, HoneyStat nodes are script-driven, automated, and cover a large IP space.

The HoneyStat nodes generate three classes of alerts: memory alerts (based on buffer overflow detection and process management), disk write alerts (such as writes to registry keys and critical files) and network alerts. Data collection is automated, and once an alert is issued, a time segment of previous traffic to the node is analyzed. A logit analysis determines what previous network activity explains the current honeypot alert. The result can indicate whether an automated or worm attack is present.

We demonstrate HoneyStat’s improvements over previous worm detection techniques. First, using trace files from worm attacks on small networks, we demonstrate how it detects zero day worms. Second, we show how it detects multi vector worms that use combinations of ports to attack. Third, the alerts from HoneyStat provide more information than traditional IDS alerts, such as binary signatures, attack vectors, and attack rates. We also use extensive (year long) trace files to show how the logit analysis produces very low false positive rates.

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