• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.481-491
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• 2020

The malicious URLs which can be used for sending malicious codes and illegally acquiring private information is one of the biggest threat of information security field. Particularly, recent prevalence of smart-phone increases the possibility of the user's exposing to malicious URLs. Since the way of hiding the URL from the user is getting more sophisticated, it is getting harder to detect it. In this paper, after conducting a survey of the user experiences related to malicious URLs, we are proposing the rule-based malicious URL detection method. In addition, we have developed java library which can be applied to any other applications which need to handle the malicious URL. Each class of the library is implementation of a rule for detecting a characteristics of a malicious URL and the library itself is the set of rule which can have the chain of rule for deteciing more complicated situation and enhancing the accuracy. This kinds of rule based approach can enhance the extensibility considering the diversity of malicious URLs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.3
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• pp.555-564
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• 2022

Recently, cyberattacks are using hacking techniques utilizing intelligent and advanced malicious codes for non-face-to-face environments such as telecommuting, telemedicine, and automatic industrial facilities, and the damage is increasing. Traditional information protection systems, such as anti-virus, are a method of detecting known malicious URLs based on signature patterns, so unknown malicious URLs cannot be detected. In addition, the conventional static analysis-based malicious URL detection method is vulnerable to dynamic loading and cryptographic attacks. This study proposes a technique for efficiently detecting malicious URLs by dynamically learning malicious URL data. In the proposed detection technique, malicious codes are classified using machine learning-based feature selection algorithms, and the accuracy is improved by removing obfuscation elements after preprocessing using Weighted Euclidean Distance(WED). According to the experimental results, the proposed machine learning-based malicious URL detection technique shows an accuracy of 89.17%, which is improved by 2.82% compared to the conventional method.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.405-414
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• 2010

According to the statistics of SecurityFocus in 2008, client-side attacks through the Microsoft Internet Explorer have increased by more than 50%. In this paper, we have implemented a behavior-based malicious web page detection system and a blacklist-based malicious web page filtering system. To do this, we first efficiently collected the target URLs by constructing a crawling system. The malicious URL detection system, run on a specific server, visits and renders actively the collected web pages under virtual machine environment. To detect whether each web page is malicious or not, the system state changes of the virtual machine are checked after rendering the page. If abnormal state changes are detected, we conclude the rendered web page is malicious, and insert it into the blacklist of malicious web pages. The malicious URL filtering system, run on the web client machine, filters malicious web pages based on the blacklist when a user visits web sites. We have enhanced system performance by automatically handling message boxes at the time of ULR analysis on the detection system. Experimental results show that the game sites contain up to three times more malicious pages than the other sites, and many attacks incur a file creation and a registry key modification.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.119-122
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• 2019

최근 웹 변조 공격은 대형 포탈, 은행, 학교 등 접속자가 많은 홈페이지에 악성 URL을 불법 삽입하여 해당 URL을 통해 접속자 PC에 자동으로 악성코드 유포하고 대규모 봇넷(botnet)을 형성한 후 DDoS 공격을 수행하거나 감염 PC들의 정보를 지속적으로 유출하는 형태로 수행된다. 이때, 홈페이지에 삽입되는 악성 URL은 탐지가 어렵도록 Javascript 난독화 기법(obfuscation technique) 등으로 은밀히 삽입된다. 본 논문에서는 웹 소스코드에 은닉된 악성 Javascript URL들에 대한 일괄 점검체계를 제안하며, 구현된 점검체계의 prototype을 활용하여 점검성능에 대한 시험결과를 제시한다.

• Convergence Security Journal
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• v.23 no.5
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• pp.101-106
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• 2023

Recently, cyberattacks are increasing in social engineering attacks using intelligent and continuous phishing sites and hacking techniques using malicious code. As personal security becomes important, there is a need for a method and a solution for determining whether a malicious URL exists using a web application. In this paper, we would like to find out each feature and limitation by comparing highly accurate techniques for detecting malicious URLs. Compared to classification algorithm models using features such as web flat panel DB and based URL detection sites, we propose an efficient URL anomaly detection technique.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.4
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• pp.921-928
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• 2016

Over the past few years, Smishing attacks such as malicious url and malicious application have been emerged as a major problem in South Korea since it caused big problems such as leakage of personal information and financial loss. Users are susceptible to Smishing attacks due to the fact that text message may contain curios content. Because of that reason, user could follow the url, download and install malicious APK file without any doubt or verification process. However currently Anti-Smishing App that adopted post-processing method is difficult to respond quickly. Users need a system that can determine whether the modification of the APK file and malicious url in real time because the Smishing can cause financial damage. This paper present the cloud-based system for verifying malicious url and malicious APK file in user device to prevent secondary damage such as smishing attacks and privacy information leakage.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.37-42
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• 2015

In this paper, we propose malware database in mobile memory for realtime malware URL detection and we support realtime malware URL detection engine, that is control the web service for more secure mobile service. Recently, mobile malware is on the rise and to be new threat on mobile environment. In particular the mobile characteristics, the damage of malware is more important, because it leads to monetary damages for the user. There are many researches in cybercriminals prevention and malware detection, but it is still insufficient. Additionally we propose the method for prevention Smishing within SMS, MMS. In the near future, mobile venders must build the secure mobile environment with fundamental measures based on our research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1786-1793
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• 2022

Cyber-attacks such as smishing and hacking mail exploiting COVID-19, political and social issues, have recently been continuous. Machine learning and deep learning technology research are conducted to prevent any damage due to cyber-attacks inducing malicious links to breach personal data. It has been concluded as a lack of basis to judge the attacks to be malicious in previous studies since the features of data set were excessively simple. In this paper, nine main features of three types, "URL Days", "URL Word", and "URL Abnormal", were proposed in addition to lexical features of URL which have been reflected in previous research. F1-Score and accuracy index were measured through four different types of machine learning algorithms. An improvement of 0.9% in a result and the highest value, 98.5%, were examined in F1-Score and accuracy through comparatively analyzing an existing research. These outcomes proved the main features contribute to elevating the values in both accuracy and performance.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.30-37
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• 2021

Various devices are connected to the Internet, and attacks using the Internet are occurring. Among such attacks, there are attacks that use malicious URLs to make users access to wrong phishing sites or distribute malicious viruses. Therefore, how to detect such malicious URL attacks is one of the important security issues. Among recent deep learning technologies, neural networks are showing good performance in image recognition, speech recognition, and pattern recognition. This neural network can be applied to research that analyzes and detects patterns of malicious URL characteristics. In this paper, performance analysis according to various parameters was performed on a method of detecting malicious URLs using neural networks. In this paper, malicious URL detection performance was analyzed while changing the activation function, learning rate, and neural network structure. The experimental data was crawled by Alexa top 1 million and Whois to build the data, and the machine learning library used TensorFlow. As a result of the experiment, when the number of layers is 4, the learning rate is 0.005, and the number of nodes in each layer is 100, the accuracy of 97.8% and the f1 score of 92.94% are obtained.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.881-891
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• 2023

Recently, various studies on malicious URL detection using artificial intelligence have been conducted, and most of the research have shown great detection performance. However, not only does classical machine learning require a process of analyzing features, but the detection performance of a trained model also depends on the data analyst's ability. In this paper, we propose a DL-ML Fusion Hybrid Model for malicious web site URL detection based on URL lexical features. the propose model combines the automatic feature extraction layer of deep learning and classical machine learning to improve the feature engineering issue. 60,000 malicious and normal URLs were collected for the experiment and the results showed 23.98%p performance improvement in maximum. In addition, it was possible to train a model in an efficient way with the automation of feature engineering.