• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.305-313
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• 2018

With the explosive growth of smart phones and efficiency, the Android of an open mobile operating system is gradually increasing in the use and the availability. Android systems has proven its availability and stability in the mobile devices, the home appliances's operating systems, the IoT products, and the mechatronics. However, as the usability increases, the malicious code based on Android also increases exponentially. Unlike ordinary PCs, if malicious codes are infiltrated into mobile products, mobile devices can not be used as a lock and can be leaked a large number of personal contacts, and can be lead to unnecessary billing, and can be cause a huge loss of financial services. Therefore, we proposed a method to detect and delete malicious files in real time in order to solve this problem. In this paper, we also designed a method to detect and delete malicious codes in a more effective manner through the process of installing Android-based applications and signature-based malicious code detection method. The method we proposed and designed can effectively detect malicious code in a limited resource environment, such as mobile environments.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.5
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• pp.304-313
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• 2010

There are several methods for malware analyses. However, it is difficult to detect malware exactly with existing detection methods. Especially, malware with strong anti-debugging facilities can detect analyzer and disturb their analyses. Furthermore, it takes too much time to analyze malware. In order to resolve these problems of current analyzers, more improved analysis scheme is required. This paper suggests a dynamic binary instrumentation which supports the instruction analysis and the memory access tracing. Additionally, by supporting the API call tracing with the DLL loading analysis, our system establishes the foundation for analyzing various executable codes. Based on Xen, full-virtualization environment is built using Intel's VT technology. Windows XP can be used as a guest. We analyze representative malware using several functions of our system, and show the accuracy and efficiency enhancements in binary analyses capability of our system.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.6
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• pp.589-593
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• 2008

These days, as a side effect of the growth of the mobile devices, malwares for the mobile devices also tend to increase and become more dangerous. Because embedded Linux is one of the advanced OSes on mobile devices, a solution to preventing malwares from infecting and destroying embedded Linux will be needed. We present a scheme using signature verification for embedded Linux that prevents executallle-Infecting malwares. The proposed scheme works under collaboration between mobile devices and a server. Malware detection is delegated to the server. In a mobile device, only integrity of all executables and dynamic libraries is checked at kernel level every time by kernel modules using LSM hooks just prior to loading of executables and dynamic libraries. All procedures in the mobile devices are performed only at kernel level. In experiments with a mobile embedded device, we confirmed that the scheme is able to prevent all executable-Infecting malwares while minimizing damage caused by execution of malwares or infected files, power consumption and performance overheads caused by malware check routines.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.501-514
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• 2013

A grouping process through the similarity comparison is required to effectively classify and respond a malicious code. When we have a use of the past similarity criteria to be used in the comparison method or properties it happens a increased problem of false negatives and false positives. Therefore, in this paper we apply to choose variety of properties to complement the problem of behavior analysis on the heuristic-based of 2nd step in malicious code auto analysis system, and we suggest a similarity comparison method applying AHP (analytic hierarchy process) for properties weights that reflect the decision-making technique. Through the similarity comparison of malicious code, configured threshold is set to the optimum point between detection rates and false positives rates. As a grouping experiment about unknown malicious it distinguishes each group made by malicious code generator. We expect to apply it as the malicious group information which includes a tracing of hacking types and the origin of malicious codes in the future.

• 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 KIISE
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• v.45 no.2
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• pp.106-112
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• 2018

Recently, the number of cyber attacks using malicious code has increased. Various types of malicious code detection techniques have been researched for several years as the damage has increased. In recent years, profiling techniques have been used to identify attack groups. This paper focuses on the identification of attack groups using a detection technique that does not involve malicious code detection. The attacker is identified by using a string or a code signature of the malicious code. In addition, the detection rate is increased by adding a technique to confirm the packing file. We use Yara as a detection technique. We have research about RAT (remote access tool) that is mainly used in attack groups. Further, this paper develops a ruleset using malicious code and packer main feature signatures for RAT which is mainly used by the attack groups. It is possible to detect the attacker by detecting RAT based on the newly created ruleset.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.321-330
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• 2015

There have been found many modified malwares which could avoid detection simply by replacing a sequence of characters or a part of code. Since the existing anti-virus program performs signature-based analysis, it is difficult to detect a malware which is slightly different from the well-known malware. This paper suggests a method of detecting modified malwares by extending a hash-value based code comparison. We generated hash values for individual functions and individual code blocks as well as the whole code, and thus use those values to find whether a pair of codes are similar in a certain degree. We also eliminated some numeric data such as constant and address before generating hash values to avoid incorrectness incurred from them. We found that the suggested method could effectively find inherent similarity between original malware and its derived ones.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.199-207
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• 2013

Recently, hacking is seen as a criminal activity beyond an activity associated with curiosity in the beginning. The malignant bot which is used as an attack technique is one of the examples. Malignant Bot is one of IRC Bots and it leaks user's information with attacker's command by attacking specified IP range. This paper will discuss an access method and a movement process by analyzing shadowbot which is a kind of a malignant Bot and will suggest possible countermeasure. This study has two distinct features. First, we analyze malignant Bot by analyzing tools such as VM ware. Second, we formulate a hypothesis and will suggest possible countermeasure through analyzing malignant Bot's access method and movement. Performance evaluation will be conducted by applying possible countermeasure to see if it can prevent attacks from malignant bot.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.123-129
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• 2020

Recently, cybercrime has become increasingly difficult to track by applying new technologies such as virtualization technology and distribution tracking avoidance. etc. Therefore, there is a limit to the technology of tracking distributors based on malicious code information through static and dynamic analysis methods. In addition, in the field of cyber investigation, it is more important to track down malicious code distributors than to analyze malicious codes themselves. Accordingly, in this paper, we propose a next-generation malicious code information collection architecture to efficiently track down malicious code distributors by converging traditional analysis methods and recent information collection methods such as OSINT and Intelligence. The architecture we propose in this paper is based on the differences between the existing malicious code analysis system and the investigation point's analysis system, which relates the necessary elemental technologies from the perspective of cybercrime. Thus, the proposed architecture could be a key approach to tracking distributors in cyber criminal investigations.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.754-762
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• 2010

Nowadays, email-based targeted attacks using malcode-bearing documents have been steadily increased. To improve the success rate of the attack and avoid anti-viruses, attackers mainly employ zero-day exploits and relevant social engineering techniques. In this paper, we propose an architecture of the email vaccine cloud system to prevent targeted attacks using malcode-bearing documents. The system extracts attached document files from email messages, performs behavior analysis as well as signature-based detection in the virtual machine environment, and completely removes malicious documents from the messages. In the process of behavior analysis, the documents are regarded as malicious ones in cases of creating executable files, launching new processes, accessing critical registry entries, connecting to the Internet. The email vaccine cloud system will help prevent various cyber terrors such as information leakages by preventing email based targeted attacks.