VLDB 2026 Research / reviewers in the wild / expert
Zisis Tsiatsikas
dblp:147/1863
· DBLP profile ↗
10ranked-venue papers
6as first author
4since 2021 · last 2025
0000-0002-9481-0906ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Security and privacy · 9 · 5 first-author · 4 since 2021Computer networks · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Unmasking the hidden credential leaks in password managers and VPN clientsabstractWith the rapid growth of software services and applications, the need to secure digital assets became paramount. The introduction of Password Manager (PM) and Virtual Private Network (VPN) software was established as a prerequisite toolkit to bolster the end-user arsenal. As a matter of fact, these types of artifacts have been around for at least 25 years in various flavors, including desktop and browser-based applications. This work assesses the ability of 12 desktop PM applications, 5 browsers with integrated PM, and 12 PMs in the form of browser plugins, along with 21 VPN client applications, to effectively protect the confidentiality of secret credentials. Our analysis focuses on the period during which an app is loaded into RAM. Despite the sensitive nature of these applications, our results show that across all scenarios the majority of PM applications store plaintext passwords in the system memory; more specifically, 75% (or 9 out of 12) of desktop PM applications, 100% (5 out of 5) of browser PMs and 75% (or 9 out of 12) of PM browser plugins leak such sensitive information. In addition, 33% (or 7 out of 21) of VPN applications leak user credentials. This practice of storing cleartext sensitive information in system memory is widely recognized as a weakness, having also been registered as CWE-316. At the time of writing, merely four vendors have recognized our exploits as vulnerabilities. Three of these vendors have assigned the relevant Common Vulnerabilities and Exposures (CVE) IDs, namely CVE-2023-23349, CVE-2024-9203, and CVE-2024-50570, whereas the fourth one will issue a CVE ID once it implements the relevant fixes. The remaining vendors have either chosen to disregard or downplay the severity of this issue. Efstratios Chatzoglou, Vyron Kampourakis, Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis |
Comput. Secur. | 3 |
| 2024 | Keep Your Memory Dump Shut: Unveiling Data Leaks in Password ManagersabstractAbstract 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. Efstratios Chatzoglou, Vyron Kampourakis, Zisis Tsiatsikas, Georgios Karopoulos, Georgios Kambourakis |
SEC | 3 |
| 2023 | Bypassing antivirus detection: old-school malware, new tricksabstractBeing on a mushrooming spree since at least 2013, malware can take a large toll on any system. In a perpetual cat-and-mouse chase with defenders, malware writers constantly conjure new methods to hide their code so as to evade detection by security products. In this context, focusing on the MS Windows platform, this work contributes a comprehensive empirical evaluation regarding the detection capacity of popular, off-the-shelf antivirus and endpoint detection and response engines when facing legacy malware obfuscated via more or less uncommon but publicly known methods. Our experiments exploit a blend of seven traditional AV evasion techniques in 16 executables built in C++, Go, and Rust. Furthermore, we conduct an incipient study regarding the ability of the ChatGPT chatbot in assisting threat actors to produce ready-to-use malware. The derived results in terms of detection rate are highly unexpected: approximately half of the 12 tested AV engines were able to detect less than half of the malware variants, four AVs exactly half of the variants, while only two of the rest detected all but one of the variants. Efstratios Chatzoglou, Georgios Karopoulos, Georgios Kambourakis, Zisis Tsiatsikas |
ARES | 4 |
| 2021 | At Your Service 24/7 or Not? Denial of Service on ESInet Systems
Zisis Tsiatsikas, Georgios Kambourakis, Dimitris Geneiatakis |
TrustBus | 1 |
| 2017 | Why Snoopy Loves Online Services: An Analysis of (Lack of) Privacy in Online ServicesabstractOver the last decade online services have penetrated the market and for many of us became an integral part of our software portfolio.On the one hand online services offer flexibility in every sector of the social web, but on the other hand these pros do not come without a cost in terms of privacy.This work focuses on online services, and in particular on the possible inherent design errors which make these services an easy target for privacy invaders.We demonstrate the previous fact using a handful of real-world cases pertaining to popular online web services.More specifically, we show that despite the progress made in raising security/privacy awareness amongst all the stakeholders (developers, admins, users) and the existence of mature security/privacy standards and practices, there still exist a plethora of poor implementations that may put user's privacy at risk.We particularly concentrate on cases where a breach can happen even if the aggressor has limited knowledge about their target and/or the attack can be completed with limited resources.In this context, the main contribution of the paper at hand revolves around the demonstration of effortlessly exploiting privacy leaks existing in widely-known online services due to software development errors. Vittoria Cozza, Zisis Tsiatsikas, Mauro Conti, Georgios Kambourakis |
ICISSP | 2 |
| 2016 | Realtime DDoS Detection in SIP Ecosystems: Machine Learning Tools of the Trade
Zisis Tsiatsikas, Dimitris Geneiatakis, Georgios Kambourakis, Stefanos Gritzalis |
NSS | 1 |
| 2015 | Battling Against DDoS in SIP - Is Machine Learning-based Detection an Effective Weapon?abstractThis paper focuses on network anomaly-detection and especially the effectiveness of Machine Learning (ML) techniques in detecting Denial of Service (DoS) in SIP-based VoIP ecosystems. It is true that until now several works in the literature have been devoted to this topic, but only a small fraction of them have done so in an elaborate way. Even more, none of them takes into account high and low-rate Distributed DoS (DDoS) when assessing the efficacy of such techniques in SIP intrusion detection. To provide a more complete estimation of this potential, we conduct extensive experimentations involving 5 different classifiers and a plethora of realistically simulated attack scenarios representing a variety of (D)DoS incidents. Moreover, for DDoS ones, we compare our results with those produced by two other anomaly-based detection methods, namely Entropy and Hellinger Distance. Our results show that ML-powered detection scores a promising false alarm rate in the general case, and seems to outperform similar methods when it comes to DDoS. Zisis Tsiatsikas, Alexandros Fakis, Dimitrios Papamartzivanos, Dimitris Geneiatakis, Georgios Kambourakis, Constantinos Kolias |
SECRYPT | 1 |
| 2015 | Hidden in Plain Sight. SDP-Based Covert Channel for Botnet Communication
Zisis Tsiatsikas, Marios Anagnostopoulos, Georgios Kambourakis, Sozon Lambrou, Dimitris Geneiatakis |
TrustBus | 1 |
| 2015 | An efficient and easily deployable method for dealing with DoS in SIP services
Zisis Tsiatsikas, Dimitris Geneiatakis, Georgios Kambourakis, Angelos D. Keromytis |
Comput. Commun. | 1 |
| 2013 | A Privacy-Preserving Entropy-Driven Framework for Tracing DoS Attacks in VoIPabstractNetwork audit trails, especially those composed of application layer data, can be a valuable source of information regarding the investigation of attack incidents. Nevertheless, the analysis of log files of large volume is usually both complex (slow) and privacy-neglecting. Especially, when it comes to VoIP, the literature on how audit trails can be exploited to identify attacks remains scarce. This paper provides an entropy-driven, privacy preserving, and practical framework for detecting resource consumption attacks in VoIP ecosystems. We extensively evaluate our framework under various attack scenarios involving single and multiple assailants. The results obtained show that the proposed scheme is capable of identifying malicious traffic with a false positive alarm rate up to 3.5%. Zisis Tsiatsikas, Dimitris Geneiatakis, Georgios Kambourakis, Angelos D. Keromytis |
ARES | 1 |