• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.28-38
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• 2003

인터넷 및 보안기술의 발달과 더불어 정보시스템에 대한 침해사고도 기하급수적으로 늘어나고 있으며, 공격기술 또한 정밀화, 분산화, 대규모화되어 가고 있다. 그러나 현재 광범위하게 사용되고 있는 침입탐지 시스템들은 그러한 인터넷상의 공격들에 대한 적절한 분석이나 효율적인 대응책은 제공해 주지 못하고, 대량의 침입탐지 정보를 생성시켜 관리자의 부담을 가중시킨다. 본 논문에서는 침입탐지 시스템이 생성하는 다수의 침입탐지 정보를 분석하고 가공하여 적시적이고 효율적인 대응에 필요한 고 수준의 정보를 생성해 내고, 나아가서는 DDoS 같은 대규모의 공격까지도 조기에 탐지해 낼 수 있는 능력을 갖춘 침입탐지 정보 연관성 분석 시스템을 제안하고 제안된 시스템의 성능 평가를 실시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1517-1520
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• 2008

최근의 사이버 공격은 경쟁사에 대한 DDoS 공격과 기밀정보 유출, 일반 사용자들의 금융정보 유출, 광고성 스팸메일의 대량 발송 등 불법 행위를 대행해주고 경제적 이득을 취하려는 의도로 바뀌어 가고 있다. 그 중심에 있는 봇넷은 봇이라 불리는 감염된 호스트들의 네트워크 집단으로서 일련의 거의 모든 사이버 공격에 이용되고 있다. 이러한 봇넷은 수 많은 변종과 다양한 탐지 회피 기술로 그 세력을 확장해가고 있지만 마땅한 총괄적 대책은 미흡한 것이 현실이다. 이 논문에서는 날이 갈수록 위협을 더해가는 봇넷을 빠르게 탐지하고 대응하기 위해 ISP 사업자들 간, 혹은 국가 간에 걸친 사회 전반적인 협력을 통한 봇넷 탐지 및 관리 시스템 구조를 제안한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.25-38
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• 2017

Many security threats are occurring around the world due to the characteristics of industrial control systems that can cause serious damage in the event of a security incident including major national infrastructure. Therefore, the industrial control system network traffic should be analyzed so that it can identify the attack in advance or perform incident response after the accident. In this paper, we research the visualization technique as network forensics to enable reasonable suspicion of all possible attacks on DNP3 control system protocol, and define normal action based rules and derive visualization requirements. As a result, we developed a visualization tool that can detect sudden network traffic changes such as DDoS and attacks that contain anormal behavior from captured packet files on industrial control system network. The suspicious behavior in the industrial control system network can be found using visualization tool with Digital Bond packet.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.1-8
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• 2021

With the rapid increase in the use of IoT and mobile devices, cyber criminals targeting IoT devices are also on the rise. Among IoT devices, when using a wireless access point (AP), problems such as packets being exposed to the outside due to their own security vulnerabilities or easily infected with malicious codes such as bots, causing DDoS attack traffic, are being discovered. Therefore, in this study, in order to actively respond to cyber attacks targeting IoT devices that are rapidly increasing in recent years, we proposed a method to collect traces of intrusion incidents artifacts from IoT devices, and to improve the validity of intrusion analysis data. Specifically, we presented a method to acquire and analyze digital forensics artifacts in the compromised system after identifying the causes of vulnerabilities by reproducing the behavior of the sample IoT malware. Accordingly, it is expected that it will be possible to establish a system that can efficiently detect intrusion incidents on targeting large-scale IoT devices.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.1
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• pp.47-55
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• 2009

Bot is a kind of worm/virus that is remotely controlled by a herder. Bot can be used to launch distributed denial-of-service(DDoS) attacks or send spam e-mails etc. Launching cyber attacks using malicious Bots is motivated by increased monetary gain which is not the objective of worm/virus. However, it is very difficult for infected user to detect this infection of Botnet which becomes more serious problems. This is why botnet is a dangerous, malicious program. The Bot DNS Sinkhole is a domestic bot mitigation scheme which will be proved in this paper as one of an efficient ways to prevent malicious activities caused by bots and command/control servers. In this paper, we analysis botnet activities over more than one-year period, including Bot's lifetime, Bot command/control server's characterizing. And we analysis more efficient ways to prevent botnet activities. We have showed that DNS sinkhole scheme is one of the most effective Bot mitigation schemes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1670-1675
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• 2020

In this study, to provide the basis for establishing effective network based countermeasures against DRDoS(Distributed Reflection Denial of Service) attacks, we propose a new 'DRDoS attack multi-level detection method' that identifies the network based characteristics of DRDoS and applies probability and statistical techniques. The proposed method removes the limit to which normal traffic can be indiscriminately blocked by unlimited competition in network bandwidth by amplification of reflectors, which is characteristic of DRDoS. This means that by comparing 'Server to Server' and 'Outbound Session Incremental' for it, accurate DRDoS identification and detection is possible and only statistical and probabilistic thresholds are applied to traffic. Thus, network-based information security systems can take advantage of this to completely eliminate DRDoS attack frames. Therefore, it is expected that this study will contribute greatly to identifying and responding to DRDoS attacks.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.180-181
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• 2014

서버 하드웨어 성능 향상과 가상화 소프트웨어 기술의 발달로 클라우드 컴퓨팅 환경은 꾸준히 확산되고 있으며, 이에 따라 인터넷 트래픽 또한 대용량화와 집중화가 진행 중이다. 이와 함께, 지속적인 DDoS 공격 및 사이버테러는 전자정부, 금융, 등 모든 조직을 대상으로 꾸준하게 일어나고 있다. 다양한 사이버테러 공격에 대응하고, 대용량 클라우드 서비스 트래픽을 정밀 분석 하는 정책서버 기반의 서비스별/사용자별/그룹별 트래픽 모니터링 및 제어 관리가 필요하다. 본 논문에서 이를 위한 오픈플로우 기반의 고성능 Open DPI(Deep Packet Inspection) 플랫폼 구조를 제안한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.107-108
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• 2022

오늘날 도메인 네임 시스템(DNS) 서비스는 단순히 IP 주소를 .com, .net 등의 도메인으로 변환해주는 기능을 넘어 컨텐츠 가속(CDN) 서비스, 고가용성(HA) 서비스, 분산 서비스 거부공격(DDoS) 방어 서비스, 통신 구간 암호화 서비스로서 그 용도를 넓혀가고 있다. 이용자들은 이러한 업체가 외부 기관에 정보를 넘기지 않고, 모든 통신 구간은 서비스 업체도 그 내용을 들여다보지 못할 정도로 철저히 암호화한다는 도덕적인 영업과 운영을 할 것으로 기대하지만, 실제 사례를 살펴보면 그렇지 못하다는 점이 드러난다. 본 논문에서는 2021년 기준으로 최소 7년간 이어져온 것으로 추정되는 유명 DNS 서비스 업체의 보안접속 악용 사례를 중심으로 이러한 악용이 어떻게 이루어지고 이것에 대응하기 위해 사용할 수 있는 표준화 기술은 이 문제에 효용성이 있는지를 DNS 업체와 동일한 실제 환경 구성을 통해 검증하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.155-163
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• 2014

To enhance network efficiency, content-centric networking (CCN) proposes that intermediated network nodes on a content-delivery path temporally cache transmitted contents. Then if an intermediated node receives a content request message (Interest) for previously cached content, the node directly transmits the cached content as a response message (Data) to requestors and finishes the transmission of the received Interest. Since Interest is performed by intermediated network nodes, it is possible to efficiently transmit contents and to effectively solve a network congestion problem caused around contents sources. For that, CCN utilizes both content store to temporarily cache content and pending Interest table (PIT) to record Interest incoming Face. However, it has mentioned the possibility of denial service attack using both the limitation of PIT resource and fake Interests. In this paper, we briefly describe the presented PIT flooding attack utilizing fake Interest. Then we introduce new attack possibility using fake Data and propose a countermeasure for the proposed attack. Also we evaluate the performance of our proposal.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.83-93
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• 2009

In recent years, cyber crimes were intended to get financial benefits through malicious attempts such as DDoS attacks, stealing financial information and spamming. Botnets, a network composed of large pool of infected hosts, lead such malicious attacks. The botnets have adopted several evasion techniques and variations. Therefore, it is difficult to detect and eliminate them. Current botnet solutions use a signature based detection mechanism. Furthermore, the solutions cannot cover broad areas enough to detect world-wide botnets. In this study, we suggest an architecture to detect and regulate botnets using cooperative design which includes modules of gathering network traffics and sharing botnet information between ISPs or nations. Proposed architecture is effective to reveal evasive and world-wide botnets, because it does not depend on specific systems or hardwares, and has broadband cooperative framework.