Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Georgios Karopoulos has a total of 33 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Large Language Models for Cyber Threat Intelligence: Extracting MITRE With LLMs

    by Andraž Krašovec, Gary Steri, Georgios Karopoulos, Mirko Trapani

    Cyber Threat Intelligence (CTI) reports provide information about emerging and current cyber threats, and their analysis is key for adopting appropriate countermeasures. Reports are typically in the form of long texts from which cybersecurity analysts extract essential elements and translate them into actionable steps. To summarise and share the findings of this analysis, sentences in the reports are often labelled with MITRE ATT&CK techniques that yield a better description of the identified attack patterns. However, this task can be very time-consuming and prone to both errors and biases of analysts. In the literature, there have been some attempts to automate this process. Most commonly, researchers apply different pre-processing steps on the initial reports and then apply classification techniques, including approaches based on large language models (LLMs). Considering that reports are written in natural language, in this paper, we present an approach that relies entirely on LLMs and seeks to minimise preprocessing of reports and other human intervention, if not to replace, at least to ease the task of the analysts. We evaluate our approach on a real-world CTI report and an extensive dataset of MITRE-labelled sentences and reduce the number of potentially suitable techniques by up to 33 $$\times $$ × while retaining ground truth labels in up to 94.29% of the sentences.


  • Top Cited Papers
    Open Access

    Intrusion Detection Based on Federated Learning: A Systematic Review

    by Jose Luis Hernandez-Ramos, Georgios Karopoulos, Efstratios Chatzoglou, Vasileios Kouliaridis, Enrique Marmol, Aurora Gonzalez-Vidal, Georgios Kambourakis

    The evolution of cybersecurity is closely linked to the development and improvement of artificial intelligence (AI). As a key tool for realizing more cybersecure ecosystems, Intrusion Detection Systems (IDSs) have evolved tremendously in recent years by integrating machine learning (ML) techniques to detect increasingly sophisticated cybersecurity attacks hidden in big data. However, traditional approaches rely on centralized learning, in which data from end nodes are shared with data centers for analysis. Recently, the application of federated learning (FL) in this context has attracted great interest to come up with collaborative intrusion detection approaches where data does not need to be shared. Due to the recent rise of this field, this work presents a complete, contemporary taxonomy for FL-enabled IDS approaches that stems from a comprehensive survey of the literature from 2018 to 2022. Precisely, our discussion includes an analysis of the main ML models, datasets, aggregation functions, as well as implementation libraries employed by the proposed FL-enabled IDS approaches. On top of everything else, we provide a critical view of the current state of the research around this topic, and describe the main challenges and future directions based on the analysis of the literature and our own experience in this area.


  • Open Access

    Assessing the Effectiveness of LLMs in Android Application Vulnerability Analysis

    by Vasileios Kouliaridis, Georgios Karopoulos, Georgios Kambourakis

    The increasing frequency of attacks on Android applications coupled with the recent popularity of large language models (LLMs) necessitates a comprehensive understanding of the capabilities of the latter in identifying potential vulnerabilities, which is key to mitigate the overall risk. To this end, the work at hand compares the ability of nine state-of-the-art LLMs to detect Android code vulnerabilities listed in the latest Open Worldwide Application Security Project (OWASP) Mobile Top 10. Each LLM was evaluated against an open dataset of over 100 vulnerable code samples, assessing each model’s ability to identify key vulnerabilities. Our analysis reveals the strengths and weaknesses of each LLM, identifying important factors that contribute to their performance. Additionally, we offer insights into context augmentation with retrieval-augmented generation (RAG) for detecting Android code vulnerabilities, which in turn may propel secure application development. Finally, while the reported findings regarding code vulnerability analysis show promise, they also reveal significant discrepancies among the different LLMs.


  • Open Access

    Unmasking the hidden credential leaks in password managers and VPN clients

    by Efstratios Chatzoglou, Vyron Kampourakis, Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis


  • Open Access

    Keep Your Memory Dump Shut: Unveiling Data Leaks in Password Managers

    by Efstratios Chatzoglou, Vyron Kampourakis, Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis

    Password management has long been a persistently challenging task. This led to the introduction of password management software, which has been around for at least 25 years in various forms, including desktop and browser-based applications. This work assesses the ability of two dozen password managers, 12 desktop applications, and 12 browser plugins, to effectively protect the confidentiality of secret credentials in six representative scenarios. Our analysis focuses on the period during which a Password Manager (PM) resides in the RAM. Despite the sensitive nature of these applications, our results show that across all scenarios, only three desktop PM applications and two browser plugins do not store plaintext passwords in the system memory. Oddly enough, at the time of writing, only two vendors recognized the exploit as a vulnerability, reserving CVE-2023-23349, while the rest chose to disregard or underrate the issue.


  • Open Access

    Keep your memory dump shut: Unveiling data leaks in password managers

    by Efstratios Chatzoglou, Vyron Kampourakis, Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis

    Password management has long been a persistently challenging task. This led to the introduction of password management software, which has been around for at least 25 years in various forms, including desktop and browser-based applications. This work assesses the ability of two dozen password managers, 12 desktop applications, and 12 browser-plugins, to effectively protect the confidentiality of secret credentials in six representative scenarios. Our analysis focuses on the period during which a Password Manager (PM) resides in the RAM. Despite the sensitive nature of these applications, our results show that across all scenarios, only three desktop PM applications and two browser plugins do not store plaintext passwords in the system memory. Oddly enough, at the time of writing, only two vendors recognized the exploit as a vulnerability, reserving CVE-2023-23349, while the rest chose to disregard or underrate the issue.

  • Open Access

    Correction to: The Effects of the Russo-Ukrainian War on Network Infrastructures Through the Lens of BGP

    by Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis

  • Open Access

    Bypassing antivirus detection: old-school malware, new tricks

    by Efstratios Chatzoglou, Georgios Karopoulos, Georgios Kambourakis, Zisis Tsiatsikas


  • Open Access

    Assessing the Security and Privacy of Android Official ID Wallet Apps

    by Vasileios Kouliaridis, Georgios Karopoulos, Georgios Kambourakis

    With the increasing use of smartphones for a wide variety of online services, states and countries are issuing official applications to store government-issued documents that can be used for identification (e.g., electronic identity cards), health (e.g., vaccination certificates), and transport (e.g., driver’s licenses). However, the privacy and security risks associated with the storage of sensitive personal information on such apps are a major concern. This work presents a thorough analysis of official Android wallet apps, focusing mainly on apps used to store identification documents and/or driver’s licenses. Specifically, we examine the security and privacy level of such apps using three analysis tools and discuss the key findings and the risks involved. We additionally explore Android app security best practices and various security measures that can be employed to mitigate these risks, such as updating deprecated components and libraries. Altogether, our findings demonstrate that, while there are various security measures available, there is still a need for more comprehensive solutions to address the privacy and security risks associated with the use of Android wallet apps.