770 research outputs found
Automatic Dataset Labelling and Feature Selection for Intrusion Detection Systems
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Correctly labelled datasets are commonly required. Three particular scenarios are highlighted, which showcase this need. When using supervised Intrusion Detection Systems (IDSs), these systems need labelled datasets to be trained. Also, the real nature of the analysed datasets must be known when evaluating the efficiency of the IDSs when detecting intrusions. Another scenario is the use of feature selection that works only if the processed datasets are labelled. In normal conditions, collecting labelled datasets from real networks is impossible. Currently, datasets are mainly labelled by implementing off-line forensic analysis, which is impractical because it does not allow real-time implementation. We have developed a novel approach to automatically generate labelled network traffic datasets using an unsupervised anomaly based IDS. The resulting labelled datasets are subsets of the original unlabelled datasets. The labelled dataset is then processed using a Genetic Algorithm (GA) based approach, which performs the task of feature selection. The GA has been implemented to automatically provide the set of metrics that generate the most appropriate intrusion detection results
Using the Pattern-of-Life in Networks to Improve the Effectiveness of Intrusion Detection Systems
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.As the complexity of cyber-attacks keeps increasing, new and more robust detection mechanisms need to be developed. The next generation of Intrusion Detection Systems (IDSs) should be able to adapt their detection characteristics based not only on the measureable network traffic, but also on the available high- level information related to the protected network to improve their detection results. We make use of the Pattern-of-Life (PoL) of a network as the main source of high-level information, which is correlated with the time of the day and the usage of the network resources. We propose the use of a Fuzzy Cognitive Map (FCM) to incorporate the PoL into the detection process. The main aim of this work is to evidence the improved the detection performance of an IDS using an FCM to leverage on network related contextual information. The results that we present verify that the proposed method improves the effectiveness of our IDS by reducing the total number of false alarms; providing an improvement of 9.68% when all the considered metrics are combined and a peak improvement of up to 35.64%, depending on particular metric combination
Cloaking the Clock: Emulating Clock Skew in Controller Area Networks
Automobiles are equipped with Electronic Control Units (ECU) that communicate
via in-vehicle network protocol standards such as Controller Area Network
(CAN). These protocols are designed under the assumption that separating
in-vehicle communications from external networks is sufficient for protection
against cyber attacks. This assumption, however, has been shown to be invalid
by recent attacks in which adversaries were able to infiltrate the in-vehicle
network. Motivated by these attacks, intrusion detection systems (IDSs) have
been proposed for in-vehicle networks that attempt to detect attacks by making
use of device fingerprinting using properties such as clock skew of an ECU. In
this paper, we propose the cloaking attack, an intelligent masquerade attack in
which an adversary modifies the timing of transmitted messages in order to
match the clock skew of a targeted ECU. The attack leverages the fact that,
while the clock skew is a physical property of each ECU that cannot be changed
by the adversary, the estimation of the clock skew by other ECUs is based on
network traffic, which, being a cyber component only, can be modified by an
adversary. We implement the proposed cloaking attack and test it on two IDSs,
namely, the current state-of-the-art IDS and a new IDS that we develop based on
the widely-used Network Time Protocol (NTP). We implement the cloaking attack
on two hardware testbeds, a prototype and a real connected vehicle, and show
that it can always deceive both IDSs. We also introduce a new metric called the
Maximum Slackness Index to quantify the effectiveness of the cloaking attack
even when the adversary is unable to precisely match the clock skew of the
targeted ECU.Comment: 11 pages, 13 figures, This work has been accepted to the 9th ACM/IEEE
International Conference on Cyber-Physical Systems (ICCPS
Using metrics from multiple layers to detect attacks in wireless networks
The IEEE 802.11 networks are vulnerable to numerous wireless-specific attacks. Attackers can implement MAC address spoofing techniques to launch these attacks, while masquerading themselves behind a false MAC address. The implementation of Intrusion Detection Systems has become fundamental in the development of security infrastructures for wireless networks. This thesis proposes the designing a novel security system that makes use of metrics from multiple layers of observation to produce a collective decision on whether an attack is taking place.
The Dempster-Shafer Theory of Evidence is the data fusion technique used to combine the evidences from the different layers. A novel, unsupervised and self- adaptive Basic Probability Assignment (BPA) approach able to automatically adapt its beliefs assignment to the current characteristics of the wireless network is proposed. This BPA approach is composed of three different and independent statistical techniques, which are capable to identify the presence of attacks in real time. Despite the lightweight processing requirements, the proposed security system produces outstanding detection results, generating high intrusion detection accuracy and very low number of false alarms. A thorough description of the generated results, for all the considered datasets is presented in this thesis. The effectiveness of the proposed system is evaluated using different types of injection attacks. Regarding one of these attacks, to the best of the author knowledge, the security system presented in this thesis is the first one able to efficiently identify the Airpwn attack
Are Intrusion Detection Studies Evaluated Consistently? A Systematic Literature Review
Cyberinfrastructure is increasingly becoming target of a wide spectrum of attacks from Denial of Service to large-scale defacement of the digital presence of an organization. Intrusion Detection System (IDSs) provide administrators a defensive edge over intruders lodging such malicious attacks. However, with the sheer number of different IDSs available, one has to objectively assess the capabilities of different IDSs to select an IDS that meets specific organizational requirements. A prerequisite to enable such an objective assessment is the implicit comparability of IDS literature. In this study, we review IDS literature to understand the implicit comparability of IDS literature from the perspective of metrics used in the empirical evaluation of the IDS. We identified 22 metrics commonly used in the empirical evaluation of IDS and constructed search terms to retrieve papers that mention the metric. We manually reviewed a sample of 495 papers and found 159 of them to be relevant. We then estimated the number of relevant papers in the entire set of papers retrieved from IEEE. We found that, in the evaluation of IDSs, multiple different metrics are used and the trade-off between metrics is rarely considered. In a retrospective analysis of the IDS literature, we found the the evaluation criteria has been improving over time, albeit marginally. The inconsistencies in the use of evaluation metrics may not enable direct comparison of one IDS to another
Dynamic Analysis of Executables to Detect and Characterize Malware
It is needed to ensure the integrity of systems that process sensitive
information and control many aspects of everyday life. We examine the use of
machine learning algorithms to detect malware using the system calls generated
by executables-alleviating attempts at obfuscation as the behavior is monitored
rather than the bytes of an executable. We examine several machine learning
techniques for detecting malware including random forests, deep learning
techniques, and liquid state machines. The experiments examine the effects of
concept drift on each algorithm to understand how well the algorithms
generalize to novel malware samples by testing them on data that was collected
after the training data. The results suggest that each of the examined machine
learning algorithms is a viable solution to detect malware-achieving between
90% and 95% class-averaged accuracy (CAA). In real-world scenarios, the
performance evaluation on an operational network may not match the performance
achieved in training. Namely, the CAA may be about the same, but the values for
precision and recall over the malware can change significantly. We structure
experiments to highlight these caveats and offer insights into expected
performance in operational environments. In addition, we use the induced models
to gain a better understanding about what differentiates the malware samples
from the goodware, which can further be used as a forensics tool to understand
what the malware (or goodware) was doing to provide directions for
investigation and remediation.Comment: 9 pages, 6 Tables, 4 Figure
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