49 Min.
DamianBolzoni and Emmanuele Zambon: NIDS: False Positive Reduction Through Anomaly Detection Black Hat Briefings, Europe 2007 [Audio] Presentations from the security conference.
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- Technologie
"The Achilles' heel of network IDSes lies in the large number of false positives (i.e., false attacks) that occur: practitioners as well as researchers observe that it is common for a NIDS traise thousands of mostly false alerts per day. False positives are a universal problem as they affect both signature-based and anomaly-based IDSs. Finally, attackers can overload IT personnel by forging ad-hoc packets tproduce false alerts, thereby lowering the defences of the IT infrastructure.
Our thesis is that one of the main reasons why NIDSs show a high false positive rate is that they dnot correlate input with output traffic: by observing the output determined by the alert-raising input traffic, one is capable of reducing the number of false positives in an effective manner. Tdemonstrate this, we have developed APHRODITE (Architecture for false Positives Reduction): an innovative architecture for reducing the false positive rate of any NIDS (be it signature-based or anomaly-based). APHRODITE consists of an Output Anomaly Detector (OAD) and a correlation engine; in addition, APHRODITE assumes the presence of a NIDS on the input of the system. For the OAD we developed POSEIDON (Payl Over Som for Intrusion DetectiON): a two-tier network intrusion detection architecture.
Benchmarks performed on POSEIDON and APHRODITE with DARPA 1999 dataset and with traffic dumped from a real-world public network show the effectiveness of the twsystems. APHRODITE is able treduce the rate of false alarms from 50% t100% (improving accuracy) without reducing the NIDS ability tdetect attacks (completeness)."
"The Achilles' heel of network IDSes lies in the large number of false positives (i.e., false attacks) that occur: practitioners as well as researchers observe that it is common for a NIDS traise thousands of mostly false alerts per day. False positives are a universal problem as they affect both signature-based and anomaly-based IDSs. Finally, attackers can overload IT personnel by forging ad-hoc packets tproduce false alerts, thereby lowering the defences of the IT infrastructure.
Our thesis is that one of the main reasons why NIDSs show a high false positive rate is that they dnot correlate input with output traffic: by observing the output determined by the alert-raising input traffic, one is capable of reducing the number of false positives in an effective manner. Tdemonstrate this, we have developed APHRODITE (Architecture for false Positives Reduction): an innovative architecture for reducing the false positive rate of any NIDS (be it signature-based or anomaly-based). APHRODITE consists of an Output Anomaly Detector (OAD) and a correlation engine; in addition, APHRODITE assumes the presence of a NIDS on the input of the system. For the OAD we developed POSEIDON (Payl Over Som for Intrusion DetectiON): a two-tier network intrusion detection architecture.
Benchmarks performed on POSEIDON and APHRODITE with DARPA 1999 dataset and with traffic dumped from a real-world public network show the effectiveness of the twsystems. APHRODITE is able treduce the rate of false alarms from 50% t100% (improving accuracy) without reducing the NIDS ability tdetect attacks (completeness)."
49 Min.