A Machine Learning Approach for Intrusion Detection

Master's thesis in Information- and communication technology (IKT590)Securing networks and their confidentiality from intrusions is crucial, and for this rea-son, Intrusion Detection Systems have to be employed. The main goal of this thesis is to achieve a proper detection performance of a Network Intrusion Detection System (NIDS). In this thesis, we have examined the detection efficiency of machine learning algorithms such as Neural Network, Convolutional Neural Network, Random Forestand Long Short-Term Memory. We have constructed our models so that they can detect different types of attacks utilizing the CICIDS2017 dataset. We have worked on identifying 15 various attacks present in CICIDS2017, instead of merely identifying normal-abnormal traffic. We have also discussed the reason why to use precisely this dataset, and why should one classify by attack to enhance the detection. Previous works based on benchmark datasets such as NSL-KDD and KDD99 are discussed. Also, how to address and solve these issues. The thesis also shows how the results are effected using different machine learning algorithms. As the research will demon-strate, the Neural Network, Convulotional Neural Network, Random Forest and Long Short-Term Memory are evaluated by conducting cross validation; the average score across five folds of each model is at 92.30%, 87.73%, 94.42% and 87.94%, respectively. Nevertheless, the confusion metrics was also a crucial measurement to evaluate the models, as we shall see. Keywords: Information security, NIDS, Machine Learning, Neural Network, Convolutional Neural Network, Random Forest, Long Short-Term Memory, CICIDS2017

Cross-Site Scripting (XSS) Detection Integrating Evidences in Multiple Stages

As Cross-Site Scripting (XSS) remains one of the top web security risks, people keep exploring ways to detect such attacks efficiently. So far, existing solutions only focus on the payload in a web request or a response, a single stage of a web transaction. This work proposes a new approach that integrates evidences from both a web request and its response in order to better characterize XSS attacks and separate them from normal web transactions. We first collect complete payloads of XSS and normal web transactions from two databases and extract features from them using the Word2vec technique. Next, we train two Gaussian mixture models (GMM) with these features, one for XSS transaction and one for normal web transactions. These two models can generate two probability scores for a new web transaction, which indicate how similar this web transaction is to XSS and normal traffics respectively. Finally, we put together these two GMM models in classification by combining these two probabilities to further improve detection accuracy

Detecting Cross-Site Scripting Attacks Using Machine Learning

Cross-site scripting (XSS) is one of the most frequently occurring types of attacks on web applications, hence is of importance in information security. XSS is where the attacker injects malicious code, typically JavaScript, into the web application in order to be executed in the user’s browser. Identifying that a script is malicious is an important part of the defence of a web application. This paper investigates using SVM, k-NN and Random Forests to detect and limit these attacks, whether known or unknown, by building classifiers for JavaScript code. It demonstrated that using an interesting feature set combining language syntax and behavioural features results in classifiers that give high accuracy and precision on large real world data sets without restricting attention only to obfuscation

IoT-HASS: A Framework For Protecting Smart Home Environment

While many solutions have been proposed for smart home security, the problem that no single solution fully protects the smart home environment still exists. In this research we propose a security framework to protect the smart home environment. The proposed framework includes three engines that complement each other to protect the smart home IoT devices. The first engine is an IDS/IPS module that monitors all traffic in the home network and then detects, alerts users, and/or blocks packets using anomaly-based detection. The second engine works as a device management module that scans and verifies IoT devices in the home network, allowing the user to flag any suspect device. The third engine works as a privacy monitoring module that monitors and detects information transmitted in plaintext and alerts the user if such information is detected. We call the proposed system IoT-Home Advanced Security System or IoT-HASS for short. IoT-HASS was developed using Python 3 and can be implemented in two modes of operation. The in-line mode allows the IoT-HASS to be installed in-line with the traffic inside a Raspberry Pi or a Router. In the in-line mode IoT-HASS acts as an IPS that can detect and block threats as well as alert the user. The second mode is the passive mode where IoT-HASS in not installed in-line with the traffic and can act as an IDS that passively monitors the traffic, detecting threats and alerting the user, but not blocking the attack. IoT-HASS was evaluated via four testing scenarios. It demonstrated superior performance in all testing scenarios in detecting attacks such as DDoS attacks, Brute Force Attacks, and Cross Site Scripting (XSS) Attacks. In each of the four test scenarios, we also tested the device management functionality, which we found to successfully scan and display IoT devices for the homeowner. The extensive evaluating and testing of IoT-HASS showed that IoT-HASS can successfully run in a small device such as a Raspberry Pi, and thus, it will most likely run in an embedded device as an IoT device. Our future research will concentrate on strengthening the current features of IoT-HASS to include additional functionalities

XSS-FP: Browser Fingerprinting using HTML Parser Quirks

There are many scenarios in which inferring the type of a client browser is desirable, for instance to fight against session stealing. This is known as browser fingerprinting. This paper presents and evaluates a novel fingerprinting technique to determine the exact nature (browser type and version, eg Firefox 15) of a web-browser, exploiting HTML parser quirks exercised through XSS. Our experiments show that the exact version of a web browser can be determined with 71% of accuracy, and that only 6 tests are sufficient to quickly determine the exact family a web browser belongs to