Orçun Çetin

dblp:162/1897 · DBLP profile ↗
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9ranked-venue papers
2as first author
5since 2021 · last 2024
0000-0001-9670-0295ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Security and privacy · 8 · 2 first-author · 4 since 2021Software engineering, systems software and programming languages · 1 · 1 since 2021
YearPublicationVenuePosition
2024 Assessing the Silent Frontlines: Exploring the Impact of DDoS Hacktivism in the Russo-Ukrainian War
abstract
This study assessed the impact and effectiveness of Distributed Denial of Service (DDoS) attacks during a period of about four months of the Russo-Ukrainian war, by observing the exchanges between the opposing sides. The data collection phase took place between the 28thof November 2022 and the 15thof April 2023. In total, we monitored 1,257 websites and web applications targeted in the conflict, with 633 targeted by pro-Russian and 624 by pro-Ukrainian entities. Only a small fraction (1.27%) of the targets remained unaffected, whereas 30.63% faced complete shutdowns. When considering the extent of the attacks conducted by the belligerents in the war, the attacks by pro-Russian entities showed a slightly more successful overall impact, with 36.18% of their targets were taken down, compared to 25.00% on the opposite side. Businesses demonstrated greater resilience against DDoS attacks compared to governmental and educational institutions. An in-depth analysis revealed significant differences in target categories, despite both sides primarily targeting businesses. Our findings regarding the usage of DDoS protection services among the 1,257 analysed targets showed that only 13.37% used such services. Among these minority of users, 70.24% had protection from the beginning of our analysis, while 29.76% adopted it only after experiencing attacks. We also looked into the use of geolocation-based access policies on websites targeted by pro-Ukrainian entities. Our findings indicated that most of these websites do not implement geolocation-based access restrictions. To an extent, such restrictions could have been useful for preventing some unsophisticated attacks. Surprisingly, only a small percentage (4.50%) restricted access to solely Russian addresses, while a fraction (12.56%) seemed to implement adaptive access policies in response to cyberattacks. Lastly, and quite surprisingly for us, we discovered that a significant number of targets on the Russian side were using anti-DDoS services and technology provided by countries that have for a long time imposed economic and commercial sanctions on Russia. This may or may not be strictly illegal, but it is without question against the spirit of these sanctions.
Yagiz Yilmaz, Orçun Çetin, Omer Said Ozturk, Emre Ekmekcioglu, Budi Arief, Julio César Hernández Castro
ACSAC2
2024 Dissecting Privacy Perspectives of Websites Around the World: "Aceptar Todo, Alle Akzeptieren, Accept All..."
Aysun Ogut, Berke Turanlioglu, Doruk Can Metiner, Albert Levi, Cemal Yilmaz 0001, Orçun Çetin, A. Selcuk Uluagac
USENIX Security Symposium6
2023 On ChatGPT: Perspectives from Software Engineering Students
abstract
ChatGPT, an increasingly popular Large Language Model (LLM), has found widespread acceptance, especially among the younger generation, who rely on it for various tasks, such as comprehending complex course materials and tackling homework assignments. This surge in interest has drawn the attention of researchers, leading to numerous studies that delve into the advantages and disadvantages of the upcoming LLM dominant era. In our research, we explore the influence of ChatGPT and similar models on the field of software engineering, specifically from the perspective of software engineering students. Our main objective is to gain valuable insights into their usage habits and opinions through a comprehensive survey. The survey encompassed diverse questions, addressing the specific areas where ChatGPT was utilized for assistance and gathering students’ reflections on each aspect. We found that ChatGPT has garnered widespread acceptance among software engineering students, with 93% of them utilizing it for their projects. These students expressed satisfaction with the level of assistance provided, and most intend to continue using it as a valuable tool in their work. During our investigation, we also assessed the students’ awareness of the underlying technologies behind ChatGPT. Approximately half of the students demonstrated awareness of these technologies, while 38.7% had made extra efforts to explore prompt engineering to enhance ChatGPT’s productivity. However, an important finding was that 90.6% of the students reported experiencing hallucinations during their interactions with ChatGPT. These hallucinations were shared as examples, raising significant concerns that warrant further exploration and mitigation. Moreover, we delved into potential improvements and gathered valuable recommendations, which could help ChatGPT to become even more effective and dependable in its applications.
Khadija Hanifi, Orçun Çetin, Cemal Yilmaz 0001
QRS2
2021 On the Effectiveness of Ransomware Decryption Tools
Burak Filiz, Budi Arief, Orçun Çetin, Julio César Hernández Castro
Comput. Secur.3
2021 Investigating the impact of ransomware splash screens
Yagiz Yilmaz, Orçun Çetin, Budi Arief, Julio César Hernández Castro
J. Inf. Secur. Appl.2
2020 Using Eyetracker to Find Ways to Mitigate Ransomware
abstract
Ransomware is a form of malware designed to prevent access to data by either locking out the victims from their system or encrypting some or all of their files until a ransom has been paid to the attacker. Victims would know that they had been hit by ransomware because a ransom demand (splash screen) would be displayed on their compromised device. This study aims to identify key user interface features of ransomware splash screens and see how these features affect victims' likelihood to pay, and how this information may be used to create more effective countermeasures to mitigate the threat of ransomware. We devised an experiment that contained three broad types of splash screens (Text, Time-Sensitive Counter, and Other). A total of nine splash screens were shown to each participant, from which data on the participants' eye behaviour were collected. After each splash screen, participants were also asked a set of questions that would help describe their experience and be cross-referenced with the eye tracking data to aid analysis. Our experiment collected quantitative eye tracker data and qualitative data regarding willingness to pay from 25 participants. Several key components of the splash screens such as the text, logo, images, and technical information were analysed. Comments from the participants on whether they would pay the ransom or not, and the reasons behind their decision were also recorded. We found that there is no clear indication that one type of splash screen would have a higher chance of success with regard to ransom payment. Our study revealed that there are some characteristics in splash screens that would strongly discourage some victims from paying. Further investigation will be carried out in this direction, in order to design and develop more effective countermeasures to ransomware.
Budi Arief, Andy Periam, Orçun Çetin, Julio César Hernández Castro
ICISSP3
2019 Tell Me You Fixed It: Evaluating Vulnerability Notifications via Quarantine Networks
abstract
Mechanisms for large-scale vulnerability notifications have been confronted with disappointing remediation rates. It has proven difficult to reach the relevant party and, once reached, to incentivize them to act. We present the first empirical study of a potentially more effective mechanism: quarantining the vulnerable resource until it is remediated. We have measured the remediation rates achieved by a medium-sized ISP for 1, 688 retail customers running open DNS resolvers or Multicast DNS services. These servers can be abused in UDP-based amplification attacks. We assess the effectiveness of quarantining by comparing remediation with two other groups: one group which was notified but not quarantined and another group where no action was taken. We find very high remediation rates for the quarantined users, 87%, even though they can self-release from the quarantine environment. Of those who received the email-only notification, 76% remediated. Surprisingly, over half of the customers who were not notified at all also remediated, though this is tied to the fact that many observations of vulnerable servers are transient. All in all, quarantining appears more effective than other notification and remediation mechanisms, but it is also clear that it can not be deployed as a general solution for Internet-wide notifications.
Orçun Çetin, Carlos Gañán, Lisette Altena, Samaneh Tajalizadehkhoob, Michel van Eeten
EuroS&P1
2019 Cleaning Up the Internet of Evil Things: Real-World Evidence on ISP and Consumer Efforts to Remove Mirai
Orçun Çetin, Carlos Gañán, Lisette Altena, Takahiro Kasama, Kazuki Tamiya, Ying Tie, Katsunari Yoshioka, Michel van Eeten
NDSS1
2015 An Empirical Analysis of ZeuS C&C Lifetime
abstract
Botnets continue to pose a significant threat to network-based applications and communications over the Internet. A key mitigation strategy has been to take down command and control infrastructure of the botnets. The efficiency of those mitigation methods has not been extensively studied. In this paper we investigate several observable characteristics of botnet command and controls (C&C) and estimate the variability in the survival rate of these C&Cs and the factors that are related to such variability. Furthermore, we show that different type of mitigation efforts have different impact. Kaplan-Meier analysis is performed to evaluate C&C survival ratios in the particular case of the ZeuS botnet. Using a lasso penalized Cox regression model, we identify the factors that influence the lifetime of a C&C. Location, malware family type, registrar, hosting type and popularity are the fundamental factors that explain this variability. Our results show that location and type of hosting are the two factors that affect more significantly the C&C lifetime. Thus, ZeuS C&Cs in certain regions of Asia are prone to stay online longer that those located in Europe.
Carlos Gañán, Orçun Çetin, Michel van Eeten
AsiaCCS2