• Journal of the Korea Society of Computer and Information
• /
• v.29 no.5
• /
• pp.1-10
• /
• 2024

Attackers tend to use similar vulnerabilities when finding their next target IT assets. They also continuously search for new attack targets. Therefore, it is essential to find the potential targets of attackers in advance. Our method proposes a novel approach for efficient vulnerable asset management and zero-day response. In this paper, we propose the ability to detect the IT assets that are potentially infected by the recently discovered vulnerability based on clustering and similarity results. As the experiment results, 86% of all collected assets are clustered within the same clustering. In addition, as a result of conducting a similarity calculation experiment by randomly selecting vulnerable assets, assets using the same OS and service were listed.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06c
• /
• pp.262-264
• /
• 2006

오늘날 빠른 정보화로 인한 역기능의 발생으로 인하여 침입탐지, 침입차단 및 방지 시스템들의 다양한 보안 솔루션을 도입하여 사용하고 있다. 하지만 제로 데이 공격과 같이 빠르게 확산될 경우 보안 장비에 빠르게 정책을 적용해야 하지만 보안 장비마다 각기 다른 접근 및 제어 형식으로 인하여 빠르게 대처하고 있지 못하다. 본 논문에서는 이러한 문제점을 보완하기 위해 한번의 정책 주입으로 대규모 네트워크에 설치되어 있는 보안 장비 및 네트워크 장비에 보안정책을 주입 시킬 수 있는 일괄 보안정책 관리 시스템에 대한 설계 및 구현에 대하여 논하고자 한다.

• Review of KIISC
• /
• v.23 no.1
• /
• pp.44-53
• /
• 2013

APT 공격은 특정 기업 또는 기관의 핵심 정보통신 설비에 대한 중단 또는 핵심정보의 획득을 목적으로 공격자는 장기간 동안 공격대상에 대해 IT인프라, 업무환경, 임직원 정보 등 다양한 정보를 수집하고, 이를 바탕으로 제로데이공격 사회공학적 기법 등을 이용하여 공격대상이 보유한 취약점을 수집 악용해 공격을 실행하는 것을 말한다. APT 공격의 특징은 명확한 공격대상을 정하고 장기간 동안 다양한 정보를 수집하여 취약점을 악용할 수 있는 정교한 프로그램을 사용하여 매우 치밀하게 공격을 수행하는 것으로 현존하고 있는 보안솔루션이나 기술로는 탐지와 대응이 어려운 측면이 있다. 본 논문에서는 APT 공격의 정의와 국내외 사고사례에 대한 분석, 금융권에서의 APT 공격에 대응하기 위한 관리적 방안과 기술적 방안 그리고 이에 대한 보안솔루션에 대해 검토하여 금융권에 적절한 대응방안을 제시하고자 한다.

• Review of KIISC
• /
• v.18 no.3
• /
• pp.60-73
• /
• 2008

인터넷에서 발생하고 있는 심각한 문제의 대부분이 멀웨어(Malware)로 인하여 발생하고 있으며, 전 세계적으로 전파되고 그 영향은 점점 악화되고 있다. 이 악성소프트웨어는 점점 더 복잡하여 지고 있으며, 이에 따라 멀웨어에 대한 분석도 어렵게 되고 있다. 그러므로 멀웨어 탐지 기술 및 그 특징에 대한 분석이 절실히 요구된다. 본 논문에서는 효과적인 멀웨어에 대한 탐지 및 대응기법 수립을 위하여 인터넷 멀웨어를 분류하기 위한 방법과 탐지 기법에 대하여 분석 및 고찰하고자한다. 또한 제로-데이 공격에 대응하고자 개발된 ZASMIN(N(Zero-day Attack Signature Manufacture Infrastructure) 시스템의 특징에 대하여도 간략히 기술한다.

• Journal of Internet Computing and Services
• /
• v.23 no.5
• /
• pp.79-85
• /
• 2022

Anomaly detection is a method to detect and block abnormal data flows in general users' data sets. The previously known method is a method of detecting and defending an attack based on a signature using the signature of an already known attack. This has the advantage of a low false positive rate, but the problem is that it is very vulnerable to a zero-day vulnerability attack or a modified attack. However, in the case of anomaly detection, there is a disadvantage that the false positive rate is high, but it has the advantage of being able to identify, detect, and block zero-day vulnerability attacks or modified attacks, so related studies are being actively conducted. In this study, we want to deal with these anomaly detection mechanisms, and we propose a new mechanism that performs both anomaly detection and classification while supplementing the high false positive rate mentioned above. In this study, the experiment was conducted with five configurations considering the characteristics of various algorithms. As a result, the model showing the best accuracy was proposed as the result of this study. After detecting an attack by applying the Extra Tree and Three-layer ANN at the same time, the attack type is classified using the Extra Tree for the classified attack data. In this study, verification was performed on the NSL-KDD data set, and the accuracy was 99.8%, 99.1%, 98.9%, 98.7%, and 97.9% for Normal, Dos, Probe, U2R, and R2L, respectively. This configuration showed superior performance compared to other models.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.5
• /
• pp.1027-1041
• /
• 2015

Recently, there are rapidly increasing cases of APT (Advanced Persistent Threat) attacks such as Verizon(2010), Nonghyup(2011), SK Communications(2011), and 3.20 Cyber Terror(2013), which cause leak of confidential information and tremendous damage to valuable assets without being noticed. Several anomaly detection technologies were studied to defend the APT attacks, mostly focusing on detection of obvious anomalies based on known malicious codes' signature. However, they are limited in detecting APT attacks and suffering from high false-negative detection accuracy because APT attacks consistently use zero-day vulnerabilities and have long latent period. Detecting APT attacks requires long-term analysis of data from a diverse set of sources collected over the long time, real-time analysis of the ingested data, and correlation analysis of individual attacks. However, traditional security systems lack sophisticated analytic capabilities, compute power, and agility. In this paper, we propose a Fast Data based real-time abnormal behavior detection system to overcome the traditional systems' real-time processing and analysis limitation.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.1
• /
• pp.85-94
• /
• 2014

This paper studied the detection technique using file DNA-based behavior pattern analysis in order to minimize damage to user system by malicious programs before signature or security patch is released. The file DNA-based detection technique was applied to defend against zero day attack and to minimize false detection, by remedying weaknesses of the conventional network-based packet detection technique and process-based detection technique. For the file DNA-based detection technique, abnormal behaviors of malware were splitted into network-related behaviors and process-related behaviors. This technique was employed to check and block crucial behaviors of process and network behaviors operating in user system, according to the fixed conditions, to analyze the similarity of behavior patterns of malware, based on the file DNA which process behaviors and network behaviors are mixed, and to deal with it rapidly through hazard warning and cut-off.

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

• Convergence Security Journal
• /
• v.20 no.3
• /
• pp.21-28
• /
• 2020

In recent years, hacking and malware techniques have evolved and become sophisticated and complex, and numerous cyber-attacks are constantly occurring in various fields. Among them, the most widely used route for compromise incidents such as information leakage and system destruction was found to be E-Mails. In particular, it is still difficult to detect and identify E-Mail APT attacks that employ zero-day vulnerabilities and social engineering hacking techniques by detecting signatures and conducting dynamic analysis only. Thus, there has been an increased demand for indicators of compromise (IOC) to identify the causes of malicious activities and quickly respond to similar compromise incidents by sharing the information. In this study, we propose a method of extracting various forensic artifacts required for detecting and investigating Hacking E-Mails, which account for large portion of damages in security incidents. To achieve this, we employed a digital forensic indicator method that was previously utilized to collect information of client-side incidents.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.10
• /
• pp.949-964
• /
• 2012

Our PC have been under constant threat of malicious codes and viruses today. As many new ways of cyber attacks are being developed, such as zero-day-attack, nobody's PC is guaranteed to be safe from the attacks. In case where a user uses the existing verification protocol on a unsecured PC, the user's verification information may well be threatened by sniffing or man-in-the-middle attack. Especially, deadly attacks like memory hacking would give hard time for users to even recognize any symptom of virus infection. Therefore, this paper designs secured QR-Login user verification protocol for smart devices that are ready to communicate with QR-Code and proposes a way to keep critical data safe when using the internet. This way, user would be able to safeguard his/her critical data even when under attack by unknown attacks and safely carry out extremely sensitive task, like financial trading, on the device.