2024
Autores
Fernandes, P; Ciardhuáin, SO; Antunes, M;
Publicação
PROGRESS IN PATTERN RECOGNITION, IMAGE ANALYSIS, COMPUTER VISION, AND APPLICATIONS, CIARP 2023, PT I
Abstract
The data exchange between different sectors of society has led to the development of electronic documents supported by different reading formats, namely portable PDF format. These documents have characteristics similar to those used in programming languages, allowing the incorporation of potentially malicious code, which makes them a vector for cyberattacks. Thus, detecting anomalies in digital documents, such as PDF files, has become crucial in several domains, such as finance, digital forensic analysis and law enforcement. Currently, detection methods are mostly based on machine learning and are characterised by being complex, slow and mainly inefficient in detecting zero-day attacks. This paper aims to propose a Benford Law (BL) based model to uncover manipulated PDF documents by analysing potential anomalies in the first digit extracted from the PDF document's characteristics. The proposed model was evaluated using the CIC Evasive PDFMAL-2022 dataset, consisting of 1191 documents (278 benign and 918 malicious). To classify the PDF documents, based on BL, into malicious or benign documents, three statistical models were used in conjunction with the mean absolute deviation: the parametric Pearson and the non-parametric Spearman and Cramer-Von Mises models. The results show a maximum F1 score of 87.63% in detecting malicious documents using Pearson's model, demonstrating the suitability and effectiveness of applying Benford's Law in detecting anomalies in digital documents to maintain the accuracy and integrity of information and promoting trust in systems and institutions.
2024
Autores
Areia, J; Santos, B; Antunes, M;
Publicação
Proceedings of the 21st International Conference on Security and Cryptography, SECRYPT 2024, Dijon, France, July 8-10, 2024.
Abstract
Memorising passwords poses a significant challenge for individuals, leading to the increasing adoption of password managers, particularly browser password managers. Despite their benefits to users’ daily routines, the use of these tools introduces new vulnerabilities to web and network security. This paper aims to investigate these vulnerabilities and analyse the security mechanisms of browser-based password managers integrated into Google Chrome, Microsoft Edge, Opera GX, Mozilla Firefox, and Brave. Through malware development and deployment, Dvorak is capable of extracting essential files from the browser’s password manager for subsequent decryption. To assess Dvorak functionalities we conducted a controlled security analysis across all aforementioned browsers. Our findings reveal that the designed malware successfully retrieves all stored passwords from the tested browsers when no master password is used. However, the results differ depending on whether a master password is used. A comparison between browsers is made, based on the results of the malware. The paper ends with recommendations for potential strategies to mitigate these security concerns. © 2024 by SCITEPRESS – Science and Technology Publications, Lda.
2024
Autores
Fernandes, P; Ciardhuáin, SO; Antunes, M;
Publicação
MATHEMATICS
Abstract
The increasing proliferation of cyber-attacks threatening the security of computer networks has driven the development of more effective methods for identifying malicious network flows. The inclusion of statistical laws, such as Benford's Law, and distance functions, applied to the first digits of network flow metadata, such as IP addresses or packet sizes, facilitates the detection of abnormal patterns in the digits. These techniques also allow for quantifying discrepancies between expected and suspicious flows, significantly enhancing the accuracy and speed of threat detection. This paper introduces a novel method for identifying and analyzing anomalies within computer networks. It integrates Benford's Law into the analysis process and incorporates a range of distance functions, namely the Mean Absolute Deviation (MAD), the Kolmogorov-Smirnov test (KS), and the Kullback-Leibler divergence (KL), which serve as dispersion measures for quantifying the extent of anomalies detected in network flows. Benford's Law is recognized for its effectiveness in identifying anomalous patterns, especially in detecting irregularities in the first digit of the data. In addition, Bayes' Theorem was implemented in conjunction with the distance functions to enhance the detection of malicious traffic flows. Bayes' Theorem provides a probabilistic perspective on whether a traffic flow is malicious or benign. This approach is characterized by its flexibility in incorporating new evidence, allowing the model to adapt to emerging malicious behavior patterns as they arise. Meanwhile, the distance functions offer a quantitative assessment, measuring specific differences between traffic flows, such as frequency, packet size, time between packets, and other relevant metadata. Integrating these techniques has increased the model's sensitivity in detecting malicious flows, reducing the number of false positives and negatives, and enhancing the resolution and effectiveness of traffic analysis. Furthermore, these techniques expedite decisions regarding the nature of traffic flows based on a solid statistical foundation and provide a better understanding of the characteristics that define these flows, contributing to the comprehension of attack vectors and aiding in preventing future intrusions. The effectiveness and applicability of this joint method have been demonstrated through experiments with the CICIDS2017 public dataset, which was explicitly designed to simulate real scenarios and provide valuable information to security professionals when analyzing computer networks. The proposed methodology opens up new perspectives in investigating and detecting anomalies and intrusions in computer networks, which are often attributed to cyber-attacks. This development culminates in creating a promising model that stands out for its effectiveness and speed, accurately identifying possible intrusions with an F1 of nearly 80%, a recall of 99.42%, and an accuracy of 65.84%.
2023
Autores
Carreiro, A; Silva, C; Antunes, M;
Publicação
CENTERIS 2023 - International Conference on ENTERprise Information Systems / ProjMAN - International Conference on Project MANagement / HCist - International Conference on Health and Social Care Information Systems and Technologies 2023, Porto, Portugal, November 8-10, 2023.
Abstract
Cybersecurity has a major impact on the healthcare sector, mainly due to the sensitive data and vital medical devices that, when an attack occurs, may compromise the life, safety, and well-being of the patients. However, those institutions fail on implementing correct system protection policies and providing adequate programs for cybersecurity training and raising cybersecurity awareness. Healthcare professionals develop their academic courses focusing on providing the best care for the patients, studying guidelines, treatment protocols, and diagnostic criteria. However, there are insufficient subjects dedicated to the development of digital literacy to match the requisites of the daily challenges of those professionals, with human error being the main cause of data breaches worldwide. So, developing training programs to face the cybersecurity day-to-day threats is mandatory. Broadly speaking, traditional training programs seem to fail on retaining students' motivation, engagement, and long-term knowledge acquisition, being time-consuming and challenging in scheduling and planning. To face this situation, new techniques, such as gamification, have emerged, with promising results on motivation and engagement, allowing the users to be the center of the training programs, matching the strategy to their levels of knowledge and preferences. This paper aims to identify the existing gamified approaches available, review the state-of-the-art related to gamification and cybersecurity training, and elaborates on how they can be successfully applied to training programs for healthcare professionals. © 2024 Elsevier B.V.. All rights reserved.
2022
Autores
Azinheira, B; Antunes, M; Maximiano, M; Gomes, R;
Publicação
CENTERIS 2022 - International Conference on ENTERprise Information Systems / ProjMAN - International Conference on Project MANagement / HCist - International Conference on Health and Social Care Information Systems and Technologies 2022, Hybrid Event / Lisbon, Portugal, November 9-11, 2022.
Abstract
2017
Autores
Carnaz, Gonçalo; Nogueira, Vitor Beires; Antunes, Mário;
Publicação
Abstract
Criminal investigations face a deluge of structured and unstructured
data obtained from heterogeneous sources like forensic reports
or wiretap transcriptions. In these cases, finding relevant information can be a complex task. Ontologies have been successfully applied to several domains including legal, cyber crime and digital forensics. In this paper it is proposed a framework based on ontology engineering, that provides an unified approach to represent and reason with the criminal investigation data. Moreover, this framework is applied to the specific use case of money laundering.
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