• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.523-531
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• 2003

Java applets are downloaded from web server through internet and executed in Java Virtual Machine of clients'browser. Before execution of java applets, JVM checks bytecode program with bytecode verifier and performs runtime tests with interpreter. However, these tests will not protect against undesirable runtime behavior of java applets, such as denial of service attack, email forging attack, URL spoofing attack, or annoying sound attack. In order to protect malicious applets, a technique used in this paper is java bytecode modification. This technique is used to restrict applet behavior or insert code appropriate to profiling or other monitoring efforts. Java byte modification is divided into two general forms, class-level modification involving subclassing non-final classes and method-level modification used when control over objects from final classes or interface. This paper showed that malicious applets are controlled by java bytecode modification using proxy server. This implementation does not require any changes in the web sever, JVM or web browser.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.4
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• pp.61-75
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• 2011

Recently, there is significant increasing of massive attacks, which try to infect PCs that visit websites containing pre-implanted malicious code. When visiting the websites, these hidden malicious codes can gain monetary profit or can send various cyber attacks such as BOTNET for DDoS attacks, personal information theft and, etc. Also, this kind of malicious activities is continuously increasing, and their evasion techniques become professional and intellectual. So far, the current signature-based detection to detect websites, which contain malicious codes has a limitation to prevent internet users from being exposed to malicious codes. Since, it is impossible to detect with only blacklist when an attacker changes the string in the malicious codes proactively. In this paper, we propose a novel approach that can detect unknown malicious code, which is not well detected by a signature-based detection. Our method can detect new malicious codes even though the codes' signatures are not in the pattern database of Anti-Virus program. Moreover, our method can overcome various obfuscation techniques such as the frequent change of the included redirection URL in the malicious codes. Finally, we confirm that our proposed system shows better detection performance rather than MC-Finder, which adopts pattern matching, Google's crawling based malware site detection, and McAfee.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.327-332
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• 2013

XSS is an attacker on the other party of the browser that is allowed to run the script. It is seized session of the users, or web site modulation, malicious content insertion, and phishing attack which is available. XSS attacks are stored XSS and reflected XSS. In that, two branch attacks. The form of XSS attacks are cookie sniffing, script encryption, bypass, the malignant cord diffusion, Key Logger, Mouse Sniffer, and addition of lie information addition. XSS attacks are target of attack by script language. Therefore, the countermeasure of XSS is presented and proposed to improve web security.

• Journal of Korea Multimedia Society
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• v.23 no.11
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• pp.1396-1405
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• 2020

Cyber threats such as forced personal information collection and distribution of malicious codes using malicious URLs continue to occur. In order to cope with such cyber threats, a security technologies that quickly detects malicious URLs and prevents damage are required. In a web environment, malicious URLs have various forms and are created and deleted from time to time, so there is a limit to the response as a method of detecting or filtering by signature matching. Recently, researches on detecting and predicting malicious URLs using machine learning techniques have been actively conducted. Existing studies have proposed various features and machine learning algorithms for predicting malicious URLs, but most of them are only suggesting specialized algorithms by supplementing features and preprocessing, so it is difficult to sufficiently reflect the strengths of various machine learning algorithms. In this paper, a system for predicting malicious URLs using multiple machine learning algorithms was proposed, and an experiment was performed to combine the prediction results of multiple machine learning models to increase the accuracy of predicting malicious URLs. Through experiments, it was proved that the combination of multiple models is useful in improving the prediction performance compared to a single model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.89-100
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• 2011

As the Internet usage with web browser is more increasing, the web-based malware which is distributed in websites is going to more serious problem than ever. The central type malicious website detection method based on crawling has the problem that the cost of detection is increasing geometrically if the crawling level is lowered more. In this paper, we proposed a security tool based on web browser which can detect the malicious web pages dynamically and support user's safe web browsing by stopping navigation to a certain malicious URL injected to those web pages. By applying these tools with many distributed web browser users, all those users get to participate in malicious website detection and feedback. As a result, we can detect the lower link level of websites distributed and dynamically.

• Convergence Security Journal
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• v.12 no.4
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• pp.3-8
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• 2012

Smartphones have all the recent technology integration and NFC (Near Field Communication) Technology is one of them and become an essential these days. Despite using smartphones with NFC technology widely, not many security vulnerabilities have been discovered. This paper attempts to identify characteristics and various services in NFC technology, and to present a wide range of security vulnerabilities, prevention, and policies especially in NFC Contactless technology. We describe a security vulnerability and an possible threat based on human vulnerability and traditional malware distribution technic using Peer-to-Peer network on NFC-Enabled smartphones. The vulnerability is as follows: An attacker creates a NFC tag for distributing his or her malicious code to unspecified individuals and apply to hidden spot near by NFC reader in public transport like subway system. The tag will direct smartphone users to a certain website and automatically downloads malicious codes into their smartphones. The infected devices actually help to spread malicious code using P2P mode and finally as traditional DDoS attack, a certain target will be attacked by them at scheduled time.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.102-104
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• 2011

최근 스마트폰 사용자가 빠른 속도로 늘어나면서 'QR(Quick Response)코드가 새로운 마케팅 및 정보의 전달 수단으로 크게 각광받고 있다. 또한, QR코드는 인터넷 주소(URL), 사진 및 동영상 정보, 지도 정보, 명함 정보 등을 제공하는 매우 효율적인 수단으로 작용하고 있다. 하지만 스마트폰으로 무심코 인식한 QR 코드로 인해 악성코드에 감염될 가능성이 높아 사용자 주의가 필요하다. 로그인된 웹 사이트에서 QR 코드를 읽어 웹 브라우저로 접근할 때 XSS(Cross Site Scripting)을 통해 해당 웹사이트의 로그인 정보를 획득하거나 게시판 회원정보와 같은 데이터를 수정할 수도 있기 때문이다. 이에 본 논문에서는 QR 코드의 XSS 공격에 대한 대응방안을 상세히 기술하여 QR 코드를 사용하는 유저들에게 도움이 되고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.416-419
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• 2014

스미싱(SMiShing) 공격은 문자메시지(SMS)를 이용하여 정보를 유출하거나 타인에게 피해를 주는 행위를 일컫는다. 본 논문에서는 공격자의 공격유형에 따라 스미싱을 "직접 정보 유출", "파밍/피싱 사이트 유도", "악성어플리케이션 다운로드 유도"로 분류하였고 스미싱 공격의 시나리오를 통해 스미싱 공격을 표현하였다. 그 후 스미싱 방지 기술 동향을 파악을 위한 기존의 대응 기법들을 조사를 하고 기존의 스미싱 탐지 기법인 URL 검사와 APK 파일 분석 기법을 접목시킨 스미싱 탐지 모델을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.90-99
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• 2003

Java applets are downloaded from web server through internet and executed in Java Virtual Machine of clients' browser. Before execution of java applets, JVM checks bytecode program with bytecode verifier and performs runtime tests with interpreter. However, these tests will not protect against undesirable runtime behavior of java applets, such as denial of service attack, email forging attack, URL spoofing attack, and annoying sound attack. In order to protect malicious applets, a technique used in this paper is java bytecode modification. This technique is used to restrict applet behavior or insert code appropriate to profiling or other monitoring efforts. Java byte modification is divided into two general forms, class-level modification involving subclassing non-final classes and method-level modification used when control over objects from final classes or interface. This paper showed that malicious applets are controlled by java bytecode modification using proxy server. This implementation does not require any changes in the web sever, JVM or web browser.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.125-132
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• 2011

A hierarchical Web Security System, which is a solution to various web-based attacks, seemingly is not able to keep up with the improvement of detoured or compound attacks. In this paper, we suggest an efficient detecting scheme for web-based attacks like Malware, XSS, Creating Webshell, URL Spoofing, and Exposing Private Information through monitoring HTTP outbound traffics in real time. Our proposed scheme detects web-based attacks by comparing the outbound traffics with the signatures of HTML tag or Javascript created by the attacks. Through the verification analysis under the real-attacked environment, we show that our scheme installed in a hierarchical web security system has superior detection capability for detoured web-based attacks.