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Real-time Detection and Containment of Network Attacks using QoS Regulation. Seong Soo Kim and A. L. Narasimha Reddy Computer Engineering Department of Electrical Engineering Texas A&M University {skim, reddy}@ee.tamu.edu. Outline. Introduction and Motivation Our Approach Implementation
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Real-time Detection and Containment of Network Attacks using QoS Regulation Seong Soo Kim and A. L. Narasimha Reddy Computer Engineering Department of Electrical Engineering Texas A&M University {skim, reddy}@ee.tamu.edu
Outline • Introduction and Motivation • Our Approach • Implementation • Experiments & Discussion • Conclusion Texas A & M University ICC 2005
Contents • Introduction and Motivation • Our Approach • Nature of Network Attacks in Protocol • Structure of flexible buffer management • non class-based flexible class-based buffer management • Implementation • Weighted Fair Queuing • Thresholds • Exponential Weighted Moving Average (EWMA) • Experiment & Discussion • Input Traffic by Protocol and Detection • Output Traffic by Protocol • Forwarded Traffic by Protocol • Evaluation of Anomaly Detection • Conclusion Texas A & M University ICC 2005
Attack/ Anomaly • Bandwidth attacks/anomalies, Flash crowds • DoS – Denial of Service : • TCP SYN flood, UDP flooding, ICMP echo reply • Typical Types: • Single attacker (DoS) • Multiple Attackers (DDoS) • Multiple Victims (Worm) Texas A & M University ICC 2005
Motivation (1) • Current network-centric approaches are Attack-specific • TCP SYN: by handling TCP SYN cookies or TCP SYN • ICMP : by turning off ICMP echo reply • These attack-specific approaches become ineffective with DDoS Need General & Aggregate Mechanisms • Previous studies looked at individual Flow-based Mechanisms • Partial state • RED-PD • These become ineffective with DDoS need Resource-based regulation • Link speeds are increasing • Need simple, effective mechanisms to implement at line speeds Class-based buffer management Texas A & M University ICC 2005
Motivation (2) • Class-based buffer management • Rate Control, Window Control, Weighted Fair Queuing • Always parse packets and assign to designated buffers • However, most of the time, traffic is normal • Become ineffective when traffic changes dynamically • Because of predefined fixed rates in protocol or resources • Flexible buffer management • Normal : non class-based • Attack : class-based • Monitoring during normal & Switching during attack Texas A & M University ICC 2005
Contents • Introduction and Motivation • Our Approach • Nature of Network Attacks in Protocol • Structure of flexible buffer management • non class-based flexible class-based buffer management • Implementation • Weighted Fair Queuing • Thresholds • Exponential Weighted Moving Average (EWMA) • Experiment & Discussion • Input Traffic by Protocol and Detection • Output Traffic by Protocol • Forwarded Traffic by Protocol • Evaluation of Anomaly Detection • Conclusion Texas A & M University ICC 2005
Nature of Network Attacks in Protocol Typical attacks and their protocols • Most network attacks are protocol specific • by S/W codes exploiting specific vulnerability • Various kinds of attacks staged in different protocols • Utility of class-based regulation Texas A & M University ICC 2005
RED/DropTail ICMP Class-based Output traffic TCP WFQ Classify UDP Input traffic Switch Etc. Non Class-based Output traffic detect signal All in one (ICMP, TCP, UDP, Etc.) Attack Detector RED/DropTail Structure of flexible buffer management • Non class-based management in normal times • Monitoring the ICMP traffic i(t), TCP traffic t(t), UDP traffic u(t) and ETC. traffic e(t). • Anomaly detection through the variation of the input traffic in protocol • Switching to class-based management during attack Texas A & M University ICC 2005
Contents • Introduction and Motivation • Our Approach • Nature of Network Attacks in Protocol • Structure of flexible buffer management • non class-based flexible class-based buffer management • Implementation • Weighted Fair Queuing • Thresholds • Exponential Weighted Moving Average (EWMA) • Experiment & Discussion • Input Traffic by Protocol and Detection • Output Traffic by Protocol • Forwarded Traffic by Protocol • Evaluation of Anomaly Detection • Conclusion Texas A & M University ICC 2005
The proportion of major protocols over two different traffic traces Weighted Fair Queuing • Wide-sense Stationary (WSS) property • The traffic-volume ratios of each protocol show stationary property over long-range time periods • 4 classes: ICMP, TCP, UDP and etc. • During normal times, the weights for each class (protocol) are set • These weights are adjustable according to input traffic Texas A & M University ICC 2005
Thresholds (1) • Traffic volume-based thresholds • TH: High threshold monitoring abnormal increase of specific protocol traffic • TL: Low threshold monitoring abnormal decreases • TCP usually occupies most of traffic • In case of TCP attack, attack could be detected through other protocols indirectly • Other indicators may be more sensitive Texas A & M University ICC 2005
Thresholds (2) • 3s-based threshold • The thresholds can be set as the 3s of normal distribution for individual protocol • Detection of anomalies Texas A & M University ICC 2005
Exponential Weighted Moving Average (EWMA) • For accommodating the dynamics of traffic, moving average of each protocol is applied. • Filter out short term noise • Operation Modes • Non class-based: FCFS • Class-based: Weighted round robin • Buffer management: RED or Drop-Tail Texas A & M University ICC 2005
Contents • Introduction and Motivation • Our Approach • Nature of Network Attacks in Protocol • Structure of flexible buffer management • non class-based flexible class-based buffer management • Implementation • Weighted Fair Queuing • Thresholds • Exponential Weighted Moving Average (EWMA) • Experiment & Discussion • Input Traffic by Protocol and Detection • Output Traffic by Protocol • Forwarded Traffic by Protocol • Evaluation of Anomaly Detection • Conclusion Texas A & M University ICC 2005
Real attack trace Case • KREONet2 Traces • 5 major actual attacks • 10 days long Texas A & M University ICC 2005
Input Traffic – Real attacks • The vertical lines show the 5 salient attack periods • UDP, ICMP can be detected by their variations • TCP can be detected by TCP or other variations • The last sub-figure shows the generated attack detection signal through majority voting Texas A & M University ICC 2005
Output traffic proportion by protocol in non class-based Output traffic proportion by protocol in flexible-based Output Traffic -- flexible buffer management • The traffic volume delivered • Non class-based scheduling • During attack, the protocols responsible for attack increase abruptly • Other protocols suffer from congestion • Flexible buffer management • All protocols maintain their predefined weights regardless of attack • At the onset of attack, the instantaneous peaks result from the latency of detection and switching Texas A & M University ICC 2005
Forwarded traffic proportion by protocol in non class-based Forwarded traffic proportion by protocol in flexible-based Forwarded Traffic -- flexible buffer management • Output / input traffic volume (%) • Non class-based scheduling • During attack, not only the culpable protocols but other innocent protocol decrease together • Flexible buffer management • Generally the only responsible protocol is filtered out • In 4th multi-protocol based attack, the TCP, UDP and ICMP are mitigated sequentially Texas A & M University ICC 2005
Simulated attacks • Simulated virtual attacks • Synthesized attacks + the Univ. of Auckland without attacks from NLANR • U of Auckland trace consists of only TCP, UDP and ICMP • To evaluate the sensitivity of our detector over attacks of various configurations. • Persistency • Intermittent : send malicious packets in on-off type at 3-minute interval • Persistent : continue to assault through the attack • IP address : target IP address type • Single destination : (semi) single destination • Semi-random : mixed type ( fixed portion + randomly changeable portion ) • Random : randomly generated • Port • Reserved, randomly generated and ephemeral client ports. Texas A & M University ICC 2005
Input Traffic – Simulated attacks Texas A & M University ICC 2005
Non class-based Buffer management Flexible Buffer management Output Traffic – simulated attacks Texas A & M University ICC 2005
Forwarded traffic proportion by protocol in non class-based Forwarded traffic proportion by protocol in flexible-based Forwarded Traffic by Protocol in flexible buffer • Output / input traffic volume (%) • In the 360 ~ 1080, the gradual decrease comes from not by attacks but by congestion drops, due to processing limitations of system Texas A & M University ICC 2005
Evaluation of Anomaly Detection Evaluation Results of protocol composition signals • Composite detection signal • Logical OR • Majority voting • Detection signal is used for switching the buffer management • Complexity • O(1) processing cost per packet • O(n) storage cost per sample, n is number of protocols • True Positive rate • False Positive rate • Likelihood Ratio by b/a, ideally it is infinity • Negative Likelihood Ratio by 1-b/1-a, ideally it is zero Texas A & M University ICC 2005
Contents • Introduction and Motivation • Our Approach • Nature of Network Attacks in Protocol • Structure of flexible buffer management • non class-based flexible class-based buffer management • Implementation • Weighted Fair Queuing • Thresholds • Exponential Weighted Moving Average (EWMA) • Experiment & Discussion • Input Traffic by Protocol and Detection • Output Traffic by Protocol • Forwarded Traffic by Protocol • Evaluation of Anomaly Detection • Conclusion Texas A & M University ICC 2005
Conclusion • We studied the feasibility of detecting anomalies through variations in protocol traffic. • We evaluated the effectiveness of our approach by employing real and simulated traffic traces • The protocol composition signal could be a useful signal • Real-time traffic monitoring is feasible • Simple enough to be implemented inline • Flexible buffer management effective in containing attacks Texas A & M University ICC 2005
Thank you !!http://ee.tamu.edu/~reddy Texas A & M University ICC 2005