Biblio
A distributed denial-of-service (DDoS) is a malicious attempt by attackers to disrupt the normal traffic of a targeted server, service or network. This is done by overwhelming the target and its surrounding infrastructure with a flood of Internet traffic. The multiple compromised computer systems (bots or zombies) then act as sources of attack traffic. Exploited machines can include computers and other network resources such as IoT devices. The attack results in either degraded network performance or a total service outage of critical infrastructure. This can lead to heavy financial losses and reputational damage. These attacks maximise effectiveness by controlling the affected systems remotely and establishing a network of bots called bot networks. It is very difficult to separate the attack traffic from normal traffic. Early detection is essential for successful mitigation of the attack, which gives rise to a very important role in cybersecurity to detect the attacks and mitigate the effects. This can be done by deploying machine learning or deep learning models to monitor the traffic data. We propose using various machine learning and deep learning algorithms to analyse the traffic patterns and separate malicious traffic from normal traffic. Two suitable datasets have been identified (DDoS attack SDN dataset and CICDDoS2019 dataset). All essential preprocessing is performed on both datasets. Feature selection is also performed before detection techniques are applied. 8 different Neural Networks/ Ensemble/ Machine Learning models are chosen and the datasets are analysed. The best model is chosen based on the performance metrics (DEEP NEURAL NETWORK MODEL). An alternative is also suggested (Next best - Hypermodel). Optimisation by Hyperparameter tuning further enhances the accuracy. Based on the nature of the attack and the intended target, suitable mitigation procedures can then be deployed.
The Internet, originally an academic network for the rapid exchange of information, has moved over time into the commercial media, business and later industrial communications environment. Recently, it has been included as a part of cyberspace as a combat domain. Any device connected to the unprotected Internet is thus exposed to possible attacks by various groups and individuals pursuing various criminal, security and political objectives. Therefore, each such device must be set up to be as resistant as possible to these attacks. For the implementation of small home, academic or industrial systems, people very often use small computing system Raspberry PI, which is usually equipped with the operating system Raspbian Linux. Such a device is often connected to an unprotected Internet environment and if successfully attacked, can act as a gateway for an attacker to enter the internal network of an organization or home. This paper deals with security configuration of Raspbian Linux operating system for operation on public IP addresses in an unprotected Internet environment. The content of this paper is the conduction and analysis of an experiment in which five Raspbian Linux/Raspberry PI accounts were created with varying security levels; the easiest to attack is a simulation of the device of a user who has left the system without additional security. The accounts that follow gradually add further protection and security. These accounts are used to simulate a variety of experienced users, and in a practical experiment the effects of these security measures are evaluated; such as the number of successful / unsuccessful attacks; where the attacks are from; the type and intensity of the attacks; and the target of the attack. The results of this experiment lead to formulated conclusions containing an analysis of the attack and subsequent design recommendations and settings to secure such a device. The subsequent section of the paper discusses the implementation of a simple TCP server that is configured to listen to incoming traffic on preset ports; it simulates the behaviour of selected services on these ports. This server's task is to intercept unauthorized connection attempts to these ports and intercepting attempts to communicate or attack these services. These recorded attack attempts are analyzed in detail and formulated in the conclusion, including implications for the security settings of such a device. The overall result of this paper is the recommended set up of operating system Raspbian Linux to work on public IP addresses in an unfiltered Internet environment.
State estimation is the core operation performed within the energy management system (EMS) of smart grid. Hence, the reliability and integrity of a smart grid relies heavily on the performance of sensor measurement dependent state estimation process. The increasing penetration of cyber control into the smart grid operations has raised severe concern for executing a secured state estimation process. The limitation with regard to monitoring large number of sensors allows an intruder to manipulate sensor information, as one of the soft targets for disrupting power system operations. Phasor measurement unit (PMU) can be adopted as an alternative to immunize the state estimation from corrupted conventional sensor measurements. However, the high installation cost of PMUs restricts its installation throughout the network. In this paper a graphical approach is proposed to identify minimum PMU placement locations, so as to detect any intrusion of malicious activity within the smart grid. The high speed synchronized PMU information ensures processing of secured set of sensor measurements to the control center. The results of PMU information based linear state estimation is compared with the conventional non-linear state estimation to detect any attack within the system. The effectiveness of the proposed scheme has been validated on IEEE 14 bus test system.
This paper presents hybrid system to minimize damage by zero-day attack. Proposed system consists of signature-based NIDPS, honeypot and temporary queue. When proposed system receives packet from external network, packet which is known for attack packet is dropped by signature-based NIDPS. Passed packets are redirected to honeypot, because proposed system assumes that all packets which pass NIDPS have possibility of zero-day attack. Redirected packet is stored in temporary queue and if the packet has possibility of zero-day attack, honeypot extracts signature of the packet. Proposed system creates rule that match rule format of NIDPS based on extracted signatures and updates the rule. After the rule update is completed, temporary queue sends stored packet to NIDPS then packet with risk of attack can be dropped. Proposed system can reduce time to create and apply rule which can respond to unknown attack packets. Also, it can drop packets that have risk of zero-day attack in real time.
Control systems for critical infrastructure are becoming increasingly interconnected while cyber threats against critical infrastructure are becoming more sophisticated and difficult to defend against. Historically, cyber security has emphasized building defenses to prevent loss of confidentiality, integrity, and availability in digital information and systems, but in recent years cyber attacks have demonstrated that no system is impenetrable and that control system operation may be detrimentally impacted. Cyber resilience has emerged as a complementary priority that seeks to ensure that digital systems can maintain essential performance levels, even while capabilities are degraded by a cyber attack. This paper examines how cyber security and cyber resilience may be measured and quantified in a control system environment. Load Frequency Control is used as an illustrative example to demonstrate how cyber attacks may be represented within mathematical models of control systems, to demonstrate how these events may be quantitatively measured in terms of cyber security or cyber resilience, and the differences and similarities between the two mindsets. These results demonstrate how various metrics are applied, the extent of their usability, and how it is important to analyze cyber-physical systems in a comprehensive manner that accounts for all the various parts of the system.
A cyber attack is a malicious and deliberate attempt by an individual or organization to breach the integrity, confidentiality, and/or availability of data or services of an information system of another individual or organization. Being able to attribute a cyber attack is a crucial question for security but this question is also known to be a difficult problem. The main reason why there is currently no solution that automatically identifies the initiator of an attack is that attackers usually use proxies, i.e. an intermediate node that relays a host over the network. In this paper, we propose to formalize the problem of identifying the initiator of a cyber attack. We show that if the attack scenario used by the attacker is known, then we are able to resolve the cyber attribution problem. Indeed, we propose a model to formalize these attack scenarios, that we call attack patterns, and give an efficient algorithm to search for attack pattern on a communication history. Finally, we experimentally show the relevance of our approach.
As a cyber attack which leverages social engineering and other sophisticated techniques to steal sensitive information from users, phishing attack has been a critical threat to cyber security for a long time. Although researchers have proposed lots of countermeasures, phishing criminals figure out circumventions eventually since such countermeasures require substantial manual feature engineering and can not detect newly emerging phishing attacks well enough, which makes developing an efficient and effective phishing detection method an urgent need. In this work, we propose a novel phishing website detection approach by detecting the Uniform Resource Locator (URL) of a website, which is proved to be an effective and efficient detection approach. To be specific, our novel capsule-based neural network mainly includes several parallel branches wherein one convolutional layer extracts shallow features from URLs and the subsequent two capsule layers generate accurate feature representations of URLs from the shallow features and discriminate the legitimacy of URLs. The final output of our approach is obtained by averaging the outputs of all branches. Extensive experiments on a validated dataset collected from the Internet demonstrate that our approach can achieve competitive performance against other state-of-the-art detection methods while maintaining a tolerable time overhead.