• Proceedings of the Korean Information Science Society Conference
• /
• 2005.07a
• /
• pp.133-135
• /
• 2005

인터넷에서 일어나는 침해사고 중에서 웜에 의한 피해가 가장 심각하다. 2001 년 Code Red 웜의 출현과 2003 년 SQL Slammer 웜의 출현 이후로 웜에 감염된 이후에 행동 양상을 탐지하여 대응하는 것은 웜의 피해를 최소화 하기에는 역부족이다. 웜에 의해서 감염이 되기 이전에 웜을 탐지하여 조기에 대처하는 것이 무엇보다 중요하다. 또한 이미 알려져 있는 웜에 대한 행동양상을 이용한 웜의 탐지는 신종 웜의 출현 주기가 급격히 짧아지는 현실에 능동적으로 대처할 수 없다. 현재까지 발생한 인터넷 웜은 감염시킬 대상을 선택함에 있어서 랜덤 생성기를 사용하였으며 향후 나타날 웜도 빠른 확산과 자신의 위치를 드러내지 않기 위해 랜덤 스케닝 방식을 사용할 것이다. 본 연구는 네트워크의 연결들을 행렬로 표현하고, 이 행렬의 랭크(rank)값을 구하여 랜덤성 체크를 하는 방식으로, 웜으로 인한 트래픽에서 발생하는 랜덤성을 탐지할 수 있도록 하였다. 이 방법은 네트워크에서 알려지지 않은 신종 웜을 탐지하도록 하므로, 웜에의한 확산을 조기 탐지할 수 있게 하고, 더불어 웜의 피해를 최소화 하는 것을 목적으로 한다.

• Journal of KIISE:Computing Practices and Letters
• /
• v.12 no.6
• /
• pp.339-348
• /
• 2006

Recently, many researches on detecting and responding worms due to the fatal infrastructural damages explosively damaged by automated attack tools, particularly worms. Network service vulnerability exploiting worms have high propagation velocity, exhaust network bandwidth and even disrupt the Internet. Previous worm researches focused on signature-based approaches however these days, approaches based on behavioral features of worms are more highlighted because of their low false positive rate and the attainability of early detection. In this paper, we propose a Distributed Worm Detection Model based on packet marking. The proposed model detects Worm Cycle and Infection Chain among which the behavior features of worms. Moreover, it supports high scalability and feasibility because of its distributed reacting mechanism and low processing overhead. We virtually implement worm propagation environment and evaluate the effectiveness of detecting and responding worm propagation.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.5
• /
• pp.517-521
• /
• 2008

A worm is a malware that propagates quickly from host to host without any human intervention. Need of early worm detection has changed research paradigm from signature based worm detection to the behavioral based detection. To increase effectiveness of proposed solution, in this paper we present mechanism of detection and prevention of worm in distributed fashion. Furthermore, to minimize the worm destruction; upon worm detection we propagate the possible attack aleγt to neighboring nodes in secure and organized manner. Considering worm behavior, our proposed mechanism detects worm cycles and infection chains to detect the sudden change in network performance. And our model neither needs to maintain a huge database of signatures nor needs to have too much computing power, that is why it is very light and simple. So, our proposed scheme is suitable for the ubiquitous environment. Simulation results illustrate better detection and prevention which leads to the reduction of infection rate.

• Journal of KIISE:Information Networking
• /
• v.34 no.3
• /
• pp.186-192
• /
• 2007

The virus throttling technique[5,6] is the one of well-known worm early technique. Virus throttling reduce the worm propagration by delaying connection packets artificially. However the worm detection time is not sufficiently fast as expected when the worm generated worm packets at a low rate. This is because the virus throttling technique use only delay queue length. In this paper we use the trend of weighted average delay queue length (TW AQL). By using TW AQL, the worm detection time is not only shorten at a low rate Internet worm, but also the false alarm does not largely increase. By experiment, we also proved our proposed algorithm had better performance.

• The KIPS Transactions:PartC
• /
• v.12C no.6 s.102
• /
• pp.847-854
• /
• 2005

Since the propagation speed of the Internet worms is quite fast, worm detection in early propagation stage is very important for reducing the damage. Virus throttling technique, one of many early worm detection techniques, detects the Internet worm propagation by limiting the connection requests within a certain ratio.[6, 7] The typical throttling technique increases the possibility of false detection by treating destination IP addresses independently in their delay queue managements. In addition, it uses a simple decision strategy that determines a worn intrusion if the delay queue is overflown. This paper proposes a two dimensional delay queue management technique in which the sessions with the same destination IP are linked and thus a IP is not stored more than once. The virus throttling technique with the proposed delay queue management can reduce the possibility of false worm detection, compared with the typical throttling since the proposed technique never counts the number of a IP more than once when it chicks the length of delay queue. Moreover, this paper proposes a worm detection algorithm based on weighted average queue length for reducing worm detection time and the number of worm packets, without increasing the length of delay queue. Through deep experiments, it is verified that the proposed technique taking account of the length of past delay queue as well as current delay queue forecasts the worn propagation earlier than the typical iuぉ throttling techniques do.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2001.11a
• /
• pp.153-156
• /
• 2001

Code Red, Nimda 등 최근 인터넷웜(Internet Worm)에 의한 침입은 방화벽시스템, 침입탐지시스템 등 보안제품이 존재하는 네트워크에서도 적절한 대책이 되지 않은 경향을 보이고 있다. 침입차단시스템을 통과할 수 있는 신종 취약점을 이용한 침입에는 오용방지방법(Misuse Detection)에 의한 침입탐지시스템이 침입패턴을 업데이트하기 전에 이미 네트 워크에 피해를 입힐 가능성이 크게 증가하는 것이다. 향후에도 크게 증가할 것으로 보이는 인터넷웜 공격 등에는 침입차단시스템, 침입탐지시스템 등 보안제품의 로그기록 상황과 네트워크의 보안상태를 지속적으로 감시함으로서 조기에 침입을 탐지할 수 있다. 본 논문에서는 신종 웜 공격에 의한 침입이 발생되었을 때 IDS가 탐지하지 못하는 상황에서도 침입의 흔적을 조기에 발견할 수 있는 네트워크 보안 상태변수확인방법(Network Security Parameter Matching Method)을 제안하고자 한다.

• The KIPS Transactions:PartC
• /
• v.13C no.5 s.108
• /
• pp.559-566
• /
• 2006

Virus throttling technique, one of many early worm detection techniques, detects the Internet worm propagation by limiting the connect requests within a certain ratio. The typical virus throttling detects worm occurrence by monitoring the length of delay queue with the fixed period of rate limiter. In this paper, we propose an algorithm that controls the period of rate limiter autonomically by utilizing the weighted average delay queue length and suggest various period determination policies that use the weighted average delay queue length as an input parameter. Through deep experiments, it is verified that the proposed technique is able to lessen inconvenience of users by reducing the connection delay time with haying just little effect on worm detection time.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.1C
• /
• pp.67-77
• /
• 2007

Virus throttling technique, one of many early worm detection techniques, detects Internet worm propagation by limiting connect requests within a certain ratio. The typical virus throttling controls the period of rate limiter autonomically by utilizing weighted average delay queue length to reduce connection delay time without hanving a large effect on worm detection time. In the existing virus throttling research, a minimum period of variable rate limiter is fired and a turning point which is a point that the period of rate limiter has been being decreased and starts to be increased is also fixed. However, these two performance factors have different effects on worm detection time and connection delay. In this paper, we analyze the effect of minimum period and turning point of variable rate limiter, and then propose an algorithm which determines values of performance factors by referencing current traffic pattern. Through deep experiments, it is verified that the proposed technique is more efficient in respect of reducing worm detection time and connection delay than the existing virus throttling which fixed the performance factors.

• Review of KIISC
• /
• v.15 no.3
• /
• pp.69-75
• /
• 2005

특정 또는 불특정 네트워크를 공격 대상으로 하는 인터넷 웜, 분산서비스거부 공격 등의 출현과 가공할 파괴력으로 인해 네트워크에 대한 보안 요구가 점차 증가하고 있다. 침입탐지시스템 등의 네트워크 보안 솔루션은 네트워크 공격에 대한 감시 및 차단 등의 기능을 제공하며 기술적인 진화를 거듭하고 있지만, 근본적인 한계로써 국부 감시로 인한 불명확성과 오탐에 의한 보안경보$^{1)}$ 플러딩 등이 지적되고 있다. 특히 보안경보의 플러딩 현상은 네트워크 보안 상태를 정확하게 판단하는 것을 방해함으로써 조기경보체제의 구축을 어렵게 하는 요인이 되고 있다. 최근 이러한 부분을 극복하기 위해 보안경보 간의 상호 연관성 분석에 대한 연구가 활발해 지고 있다. 본 논문에서는 보안경보에 대한 연관성 분석 동향에 대해서 논의한다. 또한 보안경보의 집단화(aggregation)를 이용한 네트워크 공격 상황 분석방안에 대해서도 논의한다. 보안경보의 집단화를 이용한 공격 상황 분석은 엄청나게 발생하는 보안경보로부터 조기경보를 위한 공격 정보의 판별과 광역 네트워크상에서 이상 현상의 탐지를 가능하게 한다. 이와 더불어 현재 ETRI에서 개발 중에 있는 네트워크 공격 상황 분석기인 NASA(Network Attack Situation Analyzer)에 대해서도 간략히 소개한다.

• Convergence Security Journal
• /
• v.5 no.4
• /
• pp.67-72
• /
• 2005

The exponential increase of malicious and criminal activities in cyber space is posing serious threat which could destabilize the foundation of modern information society. In particular, unexpected network paralysis or break-down created by the spread of malicious traffic could cause confusion and disorder in a nationwide scale, and unless effective countermeasures against such unexpected attacks are formulated in time, this could develop into a catastrophic condition. In order to solve a same problem, this paper researched early detection techniques for only early warning of cyber threats with separate way the detection due to and existing security equipment from the large network. It researched the cyber example alert system which applies the module of based honeynet from the actual large network and this technique against the malignant traffic how many probably it will be able to dispose effectively from large network.