• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.954-957
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• 2012

Recent high profile attacks have brought the attention of governments, corporations, and the general public towards the dangers posed by Advanced Persistent Threats. This paper provides an analysis of the attack vectors employed by these actors by studying several recent attacks. We present recommendations on how to best defend against these threats by better classification of critical information infrastructure and assets, people protection, penetration tests, access control, security monitoring, and patch management.

• Journal of Internet Computing and Services
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• v.22 no.1
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• pp.13-22
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• 2021

Recently network based attack technologies are rapidly advanced and intelligent, the limitations of existing signature-based intrusion detection systems are becoming clear. The reason is that signature-based detection methods lack generalization capabilities for new attacks such as APT attacks. To solve these problems, research on machine learning-based intrusion detection systems is being actively conducted. However, in the actual network environment, attack samples are collected very little compared to normal samples, resulting in class imbalance problems. When a supervised learning-based anomaly detection model is trained with such data, the result is biased to the normal sample. In this paper, we propose to overcome this imbalance problem through One-Class Anomaly Detection using an auto encoder. The experiment was conducted through the NSL-KDD data set and compares the performance with the supervised learning models for the performance evaluation of the proposed method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.847-857
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• 2019

Recently, various cyber threats such as Ransomware and APT attack are increasing by e-mail. The characteristic of such an attack is that it is important to take administrative measures by improving personal perception of security because it bypasses technological measures such as past pattern-based detection The purpose of this study is to investigate the human factors of employees who are vulnerable to spam mail attacks through field experiments and to establish future improvement plans. As a result of sending 7times spam mails to employees of a company and analyzing training report, It was confirmed that factors such as the number of training and the recipient 's gender, age, and workplace were related to the reading rate. Based on the results of this analysis, we suggest ways to improve the training and to improve the ability of each organization to carry out effective simulation training and improve the ability to respond to spam mail by awareness improvement.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.107-122
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• 2014

The DDoS attacks and the APT attacks occurred by the zombie computers simultaneously attack target systems at a fixed time, caused social confusion. These attacks require many zombie computers running attacker's commands, and unknown malware that can bypass detecion of the anti-virus products is being executed in those computers. A that time, many methods have been proposed for the detection of unknown malware against the anti-virus products that are detected using the signature. This paper proposes a method of unknown malware detection using digital forensic techniques and describes the results of experiments carried out on various samples of malware and normal files.

• Journal of Powder Materials
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• v.28 no.4
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• pp.342-351
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• 2021

Because of its unique properties, tungsten is a strategic and rare metal used in various industrial applications. However, the world's annual production of tungsten is only 84000 t. Ammonium paratungstate (APT), which is used as the main intermediate in industrial tungsten production, is usually obtained from tungsten concentrates of wolframite and scheelite by hydrometallurgical treatment. Intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid, and ammonium metatungstate can be derived from APT by thermal decomposition or chemical attack. Tungsten metal powder is produced through the hydrogen reduction of high-purity tungsten oxides, and tungsten carbide powder is produced by the reaction of tungsten powder and carbon black powder at 1300-1700℃ in a hydrogen atmosphere. Tungsten scrap can be divided into hard and soft scrap based on shape (bulk or powder). It can also be divided into new scrap generated during the production of tungsten-bearing goods and old scrap collected at the end of life. Recycling technologies for tungsten can be divided into four main groups: direct, chemical, and semi-direct recycling, and melting metallurgy. In this review, the current status of tungsten smelting and recycling technologies is discussed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.107-122
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• 2015

Many defensive mechanisms have been evolved as new attack methods are developed. However, APT attacks using e-mail are still hard to detect and prevent. Recently, many organizations in the government sector or private sector have been hacked by malicious e-mail based APT attacks. In this paper, first, we built hacking e-mail database based on the real e-mail data which were used in attacks on the Korean government organizations in recent years. Then, we extracted features from the hacking e-mails for profiling them. We design a case vector that can describe the specific characteristics of hacking e-mails well. Finally, based on case based reasoning, we made an algorithm for retrieving the most similar case from the hacking e-mail database when a new hacking e-mail is found. As a result, hacking e-mails have common characteristics in several features such as geo-location information, and these features can be used for classifying benign e-mails and malicious e-mails. Furthermore, this proposed case based reasoning algorithm can be useful for making a decision to analyze suspicious e-mails.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.340-342
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• 2017

국내 기업과 기관을 대상으로 하는 APT(Advanced Persistent Treat) 공격은 꾸준히 발생하고 있다. 이에 대응하기 위해 보안 담당자는 다양한 보안솔루션을 도입하고 있지만, 반대로 보안 솔루션에 의해 공격당하는 사례가 발생하고 있다. 보안 솔루션에 의한 침해사고는 백신과 같은 엔드 포인트(End Point) 보안 솔루션을 공격하는 사례가 많지만, 네트워크 보안솔루션의 취약점을 이용하여 직접적으로 공격할 수 있는 가능성이 충분히 있다. 본 논문은 네트워크 보안 솔루션을 분석하여 확인한 취약점을 바탕으로 공격 시나리오를 제시한다. 이를 통해 네트워크 보안 솔루션에 의한 공격을 사전에 고려하여 대비할 수 있도록 한다.

• Electronics and Telecommunications Trends
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• v.30 no.4
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• pp.120-128
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• 2015

최근 인터넷의 거대화와 더불어 기본적으로 ISP의 오버헤드를 최소화하는 요구사항을 만족시켜 줄 수 있는 역추적기술 보장에 큰 비중을 두고 있으며, 현재 또는 차세대 인터넷에서 적용 가능한 역추적기술이 필요하다. 본 논문은 사이버 표적공격(Advanced Persistent Threats: APT)에 적용 가능한 역추적(Traceback)기술에 대한 동향을 살펴본다. 특히 기존 IP 및 TCP Connection 기반 역추적방법 중 Network 기반 Connection 추적기술인 Timing-based Approach에 대해서 상세히 살펴보며 아울러 본 논문에서 제안하는 Netflow 기반의 ON-OFF 모델 확장을 통한 Timing-based Connection Traceback Approach의 기술적 적용을 통하여 공격 시스템의 위치와 실제 해킹을 시도하는 해커의 위치가 서로 다르다 하더라도 실제 해커의 위치인 공격 근원지를 추적할 수 있는 기술적 가능성 및 전망을 소개한다.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.313-317
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• 2014

Smart-phone, PC or tablet platforms, such as smart terminals spread to the masses trying to capitalize. Smart TV also is increasing. In Korea, market size of TV is growing fast with growth of risk of hacking. In this paper, several kinds of Smart TV hacking cases are presented with the possibility of attacks against the vulnerability analysis and countermeasures. Most of the Linux operating system is open. Thus, it is vulnerable for latest hacking techniques. Most are based on the Linux OS to enhance security mount Sand-Box. However, bypass procedure using the technique, or APT attacks can avoid San-Box technique. New hacking techniques and a variety of ways will occur in the future. Therefore, this paper will develop Smart TV, and it analysis of a security threat and establishes better prepared in the future because new hacking attacks are expected to prepare more.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.31-37
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• 2015

As the forms of cyberattacks become diverse, there has been reported another case of exploiting vulnerabilities revealed while processing either a document or multimedia file that was distributed for attacking purpose, which would replace the traditional method of distributing malwares directly. The attack is based upon the observation that the softwares such as document editer or multimedia player may reveal inherent vulnerabilities on some specific inputs. The fuzzing methods that provide invalid random inputs for test purpose could discover such exploits. This paper suggests a new fuzzing method on document applications that could work in mobile environments, in order to resolve the drawback that the existing methods run only in PC environments. Our methods could effectively discover the exploits of mobile applications, and thus could be utilized as a means of dealing with APT attacks in mobile environments.