• Journal of Convergence Society for SMB
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• v.6 no.1
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• pp.17-23
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• 2016

Recently, Internet services via various devices including smartphone have become available. Because of the development of ICT, numerous hacking incidents have occurred and most of those attacks turned out to be APT attacks. APT attack means an attack method by which a hacker continues to collect information to achieve his goal, and analyzes the weakness of the target and infects it with malicious code, and being hidden, leaks the data in time. In this paper, we examine the information collection method the APT attackers use to invade the target system in a short time using big data, and we suggest and evaluate the countermeasure to protect against the attack method using big data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.595-598
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• 2014

The cyber attacks of recent attacks that target zero-day exploit security vulnerabilities before the security patch is released (Zero Day) attack, the web site is without the Lord. These attacks, those that use the vulnerability of security that is built into the software itself is in most cases, cyber attacks that use the vulnerability of the security of the source code, in particular, has a characteristic response that are difficult to security equipment. Therefore, it is necessary to eliminate the security vulnerability from step to implement the software to prevent these attacks. In this paper, we try to design a Secure Coding Guide support tool to eliminate the threat of security from the stage of implementation.

• Journal of IKEEE
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• v.26 no.3
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• pp.389-395
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• 2022

With the evolution of technology, cyber physical systems (CPSs) are being upgraded, and new types of cyber attacks are being discovered accordingly. There are many forms of cyber attack, and all cyber attacks are made to manipulate the target systems. A representative system among cyber physical systems is a cyber physical power system (CPPS), that is, a smart grid. Smart grid is a new type of power system that provides reliable, safe, and efficient energy transmission and distribution. In this paper, specific types of cyber attacks well known as false data injection attacks targeting state estimation and energy distribution of smart grid, and protection strategies for defense of these attacks and dynamic monitoring for detection are described.

• Journal of Convergence Society for SMB
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• v.5 no.2
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• pp.1-6
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• 2015

Small and medium-sized companies lack countermeasures to secure the safety of a information system. In this circumstance, they have difficulties regarding the damage to their images and legal losses, when the information is leaked. This paper examines the information leakage of the system and hacking methods including APT attacks. Especially, APT attack, Advanced Persistent Threats, means that a hacker sneaks into a target and has a latency period of time and skims all the information related to the target, and acts in the backstage and neutralize the security services without leaving traces. Because he attacks the target covering up his traces not to reveal them, the victim remains unnoticed, which increases the damage. This study examines attack methods and the process of them and seeks a countermeasure.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.205-214
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• 2019

Android uses app cache files to improve app execution performance. However, this optimization technique may raise security issues that need to be examined. In this paper, we present a practical design of "Android app cache manipulation attack" to intentionally modify the cache files of a target app, which can be misused for stealing personal information and performing malicious activities on target apps. Even though the Android framework uses a checksum-based integrity check to protect app cache files, we found that attackers can effectively bypass such checks via the modification of checksum of the target cache files. To demonstrate the feasibility of our attack design, we implemented an attack tool, and performed experiments with real-world Android apps. The experiment results show that 25 apps (86.2%) out of 29 are vulnerable to our attacks. To mitigate app cache manipulation attacks, we suggest two possible defense mechanisms: (1) checking the integrity of app cache files; and (2) applying anti-decompilation techniques.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1247-1258
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• 2018

The Cyber Kill Chain originally proposed by Lockheed Martin defines the standard procedure of general cyber attacks and suggests tailored defensive actions per each step, eventually neutralizing the intent of the attackers. Defenders can effectively deal with Advanced Persistent Threat(APT)s which are difficult to be handled by other defensive mechanisms under the Cyber Kill Chain. Recently, however, social engineering techniques that exploits the vulnerabilities of humans who manage the target systems are prevail rather than the technical attacks directly attacking the target systems themselves. Under the circumstance, the Cyber Kill Chain model should evolve to encompass social engineering attacks for the improved effectiveness. Therefore, this paper aims to establish a definite concept of Cyber Kill Chain for social engineering based cyber attacks, called Social Engineering Cyber Kill Chain, helping future researchers in this literature.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1227-1236
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• 2021

Adversarial attack, one of the attacks on deep learning classification model, is attack that add indistinguishable perturbations to input data and cause deep learning classification model to misclassify the input data. There are various adversarial attack algorithms. Accordingly, many studies have been conducted to detect adversarial attack but few studies have been conducted to classify what adversarial attack algorithms to generate adversarial input. if adversarial attacks can be classified, more robust deep learning classification model can be established by analyzing differences between attacks. In this paper, we proposed a model that detects and classifies adversarial attacks by constructing a random forest classification model with input features extracted from a target deep learning model. In feature extraction, feature is extracted from a output value of hidden layer based on class predicted by the target deep learning model. Through Experiments the model proposed has shown 3.02% accuracy on clean data, 0.80% accuracy on adversarial data higher than the result of pre-existing studies and classify new adversarial attack that was not classified in pre-existing studies.

• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.185-196
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• 2022

The Internet of Things (IoT) has become more and more widespread in recent years, thus attackers are placing greater emphasis on IoT environments. The IoT connects a large number of smart devices via wired and wireless networks that incorporate sensors or actuators in order to produce and share meaningful information. Attackers employed IoT devices as bots to assault the target server; however, because of their resource limitations, these devices are easily infected with IoT malware. The Distributed Denial of Service (DDoS) is one of the many security problems that might arise in an IoT context. DDOS attempt involves flooding a target server with irrelevant requests in an effort to disrupt it fully or partially. This worst practice blocks the legitimate user requests from being processed. We explored an intelligent intrusion detection system (IIDS) using a particular sort of machine learning, such as Artificial Neural Networks, (ANN) in order to handle and mitigate this type of cyber-attacks. In this research paper Feed-Forward Neural Network (FNN) is tested for detecting the DDOS attacks using a modified version of the KDD Cup 99 dataset. The aim of this paper is to determine the performance of the most effective and efficient Back-propagation algorithms among several algorithms and check the potential capability of ANN- based network model as a classifier to counteract the cyber-attacks in IoT environments. We have found that except Gradient Descent with Momentum Algorithm, the success rate obtained by the other three optimized and effective Back- Propagation algorithms is above 99.00%. The experimental findings showed that the accuracy rate of the proposed method using ANN is satisfactory.

• Korean Security Journal
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• no.54
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• pp.149-179
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• 2018

October 31, 2017, a man named Saipov who follows ISIS killed 8 people and injured nearly 20 others by driving his truck to the riverside bicycle path in Manhattan, New York, in an act of terror. June 5, 2017, the Islamic extremist Yacqub Khayre held a woman hostage in a suburb of Melbourne, Australia, before being killed by the police. Various countries around the world including the UK, France, and Germany are in war against terrorism. The terrorists change their target from hard targets such as government officials to vulnerable soft target, intensifying the public's fear, and, unlike in the past when they were organized by governments or organizations, extremists such as ISIS followers are now acting on their own in the act of terrorism. Also, as they use vehicles, pressure cooker, and other objects that can be easily found for terrorism, it is becoming more difficult for the police to prepare against terrorist attacks. Meanwhile, some terrorism researchers argue that conversational techniques (negotiation) used by the police are now of no use, as shown in the cases like 9/11 attacks in 2001 and 2016 Nice attack in France in which the suspects committed terrorist attacks without leaving enough time for the police to take action and that, therefore, tactical suppression techniques need to be developed. Therefore, this study suggested police negotiation techniques are necessary not only for terrorist attacks but also for overall police work, including handling intoxicated people at police station, and proposed ways to activate conversational techniques for police organizations.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.141-145
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• 2003

We propose the model of Software Rejuvenation methodology, which is applicable for survivability. Software rejuvenation is a proactive fault management technique and being used in fault tolerant systems as a cost effective technique for dealing with software faults. Survivability focuses on delivery of essential services and preservation of essential assets, even systems are penetrated and compromised. Thus, our objective is to detect the intrusions in a real time and survive in face of such attacks. As we deterrent against an attack in a system level, the Intrusion tolerance could be maximized at the target environment. We address the optimal time to execute ad hoc software rejuvenation and we compute it by using the semi Markov process. This is one way that could be really frustrated and deterred the attacks, as the attacker can't make their progress. This Software Rejuvenation method can be very effective under the assumption of unknown attacks. In this paper, we compute the optimum time to perform an ad hoc Software Rejuvenation through intrusions.