Matej Rabzelj

Mr. Matej Rabzelj

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 August 2023 in IEEE Access
Verified
Journal Article
Open access
MRMatej Rabzelj
Matej Rabzelj
Ciril BohakCiril Bohak
Ciril Bohak
LJLeon Štefanič Južnič
Leon Štefanič Južnič
Andrej KosAndrej Kos
Andrej Kos
USUrban Sedlar
Urban Sedlar
Cybersecurity research demands continuous monitoring of the dynamic threat landscape to detect novel attacks. Researchers and security professionals often deploy honeypot networks to intercept and examine real attack data. However, due to the volume and variety of the collected data, it is very challenging for security analysts to investigate the attacks, compare their characteristics and infer their potential connections. To this end, we propose a novel graph-based cyberattack model for storing, analyzing, and visualizing honeynet-captured attacks as the main contribution of our work. Our model enables attack graph analysis and presents the attack data analogous to the Cyber Kill Chain framework to enable intuitive visualizations. We construct the attack graph by decomposing the intercepted attacks into a set of unique entities (represented as nodes) and actions (represented as edges) and merge them into a global attack graph. We develop a user-centric, interactive attack analysis and visualization tool that leverages the proposed model to aid the heuristic cyberattack investigation. We describe the design and technical implementation of the developed model and visual-interactive tool in detail. Finally, we demonstrate the developed tools and validate the model in an analysis of real-world attack data captured on our own distributed honeypot platform. We use the attack model and (sub)graph visualizations to depict attack topologies, identify recurring attackers, and quantify detected malware types. We also leverage graph data science algorithms to uncover and rank malware distribution networks, reveal hidden links between the attackers, and cluster the attack entities to identify potential botnets.

17 August 2023 in Electronics
Verified
Journal Article
Open access
PDF file
MRMatej Rabzelj
Matej Rabzelj
LJLeon Štefanić Južnič
Leon Štefanić Južnič
MVMojca Volk
Mojca Volk
Andrej KosAndrej Kos
Andrej Kos
MKMatej Kren
Matej Kren
USUrban Sedlar
Urban Sedlar
Digitalization of our economy and society has ushered in notable productivity increases but has also exposed more of our infrastructures and systems to cyberattacks. This trend is exacerbated by the proliferation of poorly designed Internet of Things (IoT) devices and cloud services, which often lack appropriate security measures, either due to bugs or configuration mistakes. In this article, we propose, validate, and critically evaluate a flexible honeypot system based on the Hypertext Transfer Protocol (HTTP) that can mimic any HTTP-based service and application. This covers a large share of IoT devices, including black box devices with no software or firmware available for emulation, as well as cloud- and web-based services. We validate the system by implementing 14 services and by running a 4-month experiment, collecting data from attackers. We propose a novel data enrichment mechanism for identifying internet scanning services, as well as several other data collection and enrichment approaches. Finally, we present some results and visualizations of the data collection experiment, demonstrating possible applications and future use cases, as well as potential drawbacks of such systems.

12 June 2025 in Sensors
Verified
Journal Article
Open access
PDF file
MRMatej Rabzelj
Matej Rabzelj
USUrban Sedlar
Urban Sedlar
This study presents one of the most extensive analyses of the lifecycle of leaked authentication credentials to date, bridging the gap between database breaches and real-world cyberattacks. We analyze over 27 billion leaked credentials—nearly 4 billion unique—using a sophisticated data filtering and normalization pipeline to handle breach inconsistencies. Following this analysis, we deploy a distributed sensor network of 39 honeypots running 14 unique services across 9 networks over a one-year-long experiment, capturing one of the most comprehensive authentication datasets in the literature. We analyze leaked credentials, SSH and Telnet session data, and HTTP authentication requests for their composition, characteristics, attack patterns, and occurrence. We comparatively assess whether credentials from leaks surface in real-world attacks. We observe a significant overlap of honeypot logins with common password wordlists (e.g., Nmap, John) and defaultlists (e.g., Piata, Mirai), and limited overlaps between leaked credentials, logins, and dictionaries. We examine generative algorithms (e.g., keywalk patterns, hashcat rules), finding they are widely used by users but not attackers—unless included in wordlists. Our analyses uncover unseen passwords and methods likely designed to detect honeypots, highlighting an adversarial arms race. Our findings offer critical insights into password reuse, mutation, and attacker strategies, with implications for authentication security, attack detection, and digital forensics.