• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.125-139
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• 2013

Distribution of malicious applications developed by attackers is increasing along with general normal applications due to the openness of the Android-based open market. Mechanism that allows more accurate ways to distinguish normal apps and malicious apps for common mobile devices should be developed in order to reduce the damage caused by the rampant malicious applications. This paper analysed the normal event pattern from the most highly used game apps in the Android open market to analyse the event pattern from normal apps and malicious apps of mobile devices that are based on the Android platform, and analysed the malicious event pattern from the malicious apps and the disguising malicious apps in the form of a game app among 1260 malware samples distributed by Android MalGenome Project. As described, experiment that extracts normal app and malicious app events was performed using Strace, the Linux-based system call extraction tool, targeting normal apps and malicious apps on Android-based mobile devices. Relevance analysis for each event set was performed on collected events that occurred when normal apps and malicious apps were running. This paper successfully extracted event similarity through this process of analyzing the event occurrence characteristics, pattern and distribution on each set of normal apps and malicious apps, and lastly suggested a mechanism that determines whether any given app is malicious.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.479-490
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• 2013

Recently, the number of attacks by malicious application has significantly increased, targeting Android-platform mobile terminal such as Samsung Galaxy Note and Galaxy Tab 10.1. The malicious application can be distributed to currently used mobile devices through open market masquerading as an normal application. An attacker inserts malicious code into an application, which might threaten privacy by rooting attack. Once the rooting attack is successful, malicious code can collect and steal private data stored in mobile terminal, for example, SMS messages, contacts list, and public key certificate for banking. To protect the private information from the malicious attack, malicious code detection, rooting attack detection and countermeasure method are required. To meet this end, this paper investigates rooting attack mechanism for Android-platform mobile terminal. Based on that, this paper proposes countermeasure system that enables to extract and collect events related to attacks occurring from mobile terminal, which contributes to active protection from malicious attacks.

• Annual Conference of KIPS
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• 2015.10a
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• pp.865-866
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• 2015

스마트폰은 주로 사용되고 있는 안드로이드 OS는 다양한 악성코드로 인해 금전적 피해, 데이터 유출 및 통제권한 상실 등과 같은 많은 피해를 당하고 있다. 침해 위협을 가중시키고 있는 모바일 악성코드 중 심각한 피해를 유발하는 커널 기반의 루팅(Rooting) 악성코드는 일반적인 탐지 방법으로는 찾아낼 수 없는 어려움이 있다. 본 논문에서는 커널 기반에서 동작하는 루팅(Rooting) 악성코드를 탐지하기 위한 방법을 제안한다. 스마트폰 어플리케이션이 실행될 때마다 생성되는 모든 프로세스의 UID를 확인하여 비정상적으로 사용자(User) 권한에서 관리자(Root) 권한으로 변환되는지를 확인하는 방법이다. 제안하는 방법을 활용하여 알려지지 않은 악성코드로 인한 안드로이드 OS의 피해를 최소화할 수 있을 것으로 기대된다.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.127-134
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• 2011

Malicious botnet has been used for more malicious activities, such as DDoS attacks, sending spam messages, steal personal information, etc. To prevent this, many studies have been preceded. But malicious botnets have evolved and evaded detection systems. In particular, HTTP GET Request attack that exploits the vulnerability of the application layer is used. ALAB of ALADDIN proposed by ETRI is DDoS attack detection system that HTTP GET, Incomplete GET request flooding attack detection algorithm is applied. In this paper, we extend Incomplete GET detection algorithm of ALAB and derive the optimal configuration parameters to verify the validity of the algorithm ALAB by the study of the normal and attack packets.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.606-608
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• 2014

Recent smartphone users constantly increases, an increase in malicious applications smartphones indiscretions exists within the Terminal, through the deployment of privacy disclosure, Singh and other victims also are on the rise. A typical personal way to malicious code masquerading as a normal application and install it on the handset of my text message or a personal note, such as personal information, the certificate directory, is the way that leaked. Therefore, to obtain permission to attack the root Terminal event by collecting malware infections and respond to determine whether it is necessary for the technique. In this paper, check the features of a Smartphone in real time systems, to carry out a study on the application throughout the Terminal to collect my attack event analysis, malware infection can determine whether or not the mobile security monitoring system. This prevents a user's personal information and take advantage of the top and spill are expected to be on the field.

• Review of KIISC
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• v.23 no.2
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• pp.21-28
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• 2013

스마트폰의 급증 현상은 모바일 생태계의 패러다임을 변화시켰으며 다양한 SW 컨텐츠의 양산과 더불어 그 활용 영역의 확대를 가져왔다. 이에 따라 필연적으로 모바일 악성코드도 증가되고 있으며 개인정보 또는 회사 기밀정보의 무단 유출이라는 사회적 이슈도 대두되게 되었다. 이러한 문제를 해결하기 위해서는 모바일 어플리케이션에 대한 검증이 필요하고, 검증하는 방법에는 크게 정적분석 방법과 동적분석 방법이 있으며 분석 방법에 대한 자세한 내용은 선배 전문가들의 앞선 연구 사례와 논문에 몇 차례 소개된 바 있다. 이에 본 고에서는 정적분석 및 동적분석 방법을 응용하여 (주)안랩에서 실제로 운용 중인 모바일 어플리케이션의 분석 및 검증 솔루션(AMSD) 구현사례를 소개하고자 한다. 여기에는 기 알려진 정적분석 방법과 동적분석 방법에 대한 간략한 서술이 포함되어 있으며 시스템 아키텍처 정보와 실제 오픈 마켓을 대상으로 운용하면서 얻어진 앱 분석 사례 및 개선 방향도 담고 있다. 이를 통해 모바일 오픈 마켓 운영 시의 안전성과 신뢰성 확보 및 건전한 모바일 생태계 유지를 도모하는 데 조금이나마 도움이 되었으면 하는 바램이다.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.25-36
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• 2017

As smartphone users have increased in recent years, various applications have been developed and used especially for Android-based mobile devices. However, malicious applications developed by attackers for malicious purposes are also distributed through 3rd party open markets, and damage such as leakage of personal information or financial information of users in mobile terminals is continuously increasing. Therefore, to prevent this, a method is needed to distinguish malicious apps from normal apps for Android-based mobile terminal users. In this paper, we analyze the existing researches that detect malicious apps by extracting the system call events that occur when the app is executed. Based on this, we propose a technique to identify malicious apps by analyzing the sequence similarity of kernel layer events occurring in the process of running an app on commercial Android mobile devices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.829-838
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• 2015

As the number of smartphone users have increased, many kinds of malwares have emerged. Unlike existing malwares, spyware can be installed normally after user authentication and agreement according to security policy. For this reason, it is not easy to catch spywares involving harmful functionalities to users by using existing malware detection system. Therefore, our paper focuses on study about detecting mainly wiretapping spywares among them by developing a new wiretapping detection model and application. Specifically, this study conducts to find out power consumption on each application and modular and network consumption to detect voice wiretapping so Open Source Project Power Tutor is used to do this. The risk assessment of wiretapping is measured by gathered all power consumption data from Open Source Project Power Tutor. In addition, developed application in our study can detect at-risk wiretapping spyware through collecting and analyzing data. After we install the application to the smartphone, we collect needed data and measure it.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.429-442
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• 2020

The proportion of attacks via office documents is increasing in recent incidents. Although the security of office applications has been strengthened gradually, the attacks through the office documents are still effective due to the sophisticated use of social engineering techniques and advanced attack techniques. In this paper, we propose a method for detecting malicious OOXML(Office Open XML) documents and a framework for detection. To do this, malicious files used in the attack and benign files were collected from the malicious code repository and the search engine. By analyzing the malicious code types of collected files, we identified six "suspicious object" elements that are meaningful in determining whether they are malicious in a document. In addition, we implemented an OOXML document-based malware detection framework based on the detection method to classify the collected files and found that 98.45% of malicious filesets were detected.

• Convergence Security Journal
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• v.6 no.2
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• pp.21-29
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• 2006

Recently, illegal manipulation and forgery threats on computer softwares are increasing. Specially, forge the code of program and disrupt normal operation using a malicious loader program against the Internet application client. In this paper, we first analyze and generate signatures of malicious loader detection. And, we propose a method to secure the application client based on profiling which can detect and filter out abnormal malicious loader requests.