1. Introduction
Cloud computing has transformed IT resource management by delivering unprecedented scalability, flexibility, and cost efficiency [
1]. These advantages have driven widespread adoption across industries, enabling organizations to optimize operations and focus on innovation. However, this paradigm shift has also introduced significant security challenges, particularly concerning data exfiltration—a critical threat in which unauthorized commodities transfer sensitive information from the cloud infrastructure to external destinations. Data exfiltration compromises the confidentiality and integrity of sensitive information and exposes organizations to significant financial losses and reputational damage.
Data exfiltration can be performed using various techniques, making its detection and prevention particularly challenging [
2]. Techniques such as Domain Name System (DNS) tunneling, where data is encoded in DNS queries and responses; HTTP/S transfers, which exploit common, often unmonitored web traffic; and covert channels, which use unconventional methods to transmit data, are among the most prevalent techniques employed by malicious actors. These techniques bypass traditional security measures and require advanced specialized tools to detect and mitigate them effectively.
Several high-profile cyber-espionage incidents have revealed the use of covert tunneling techniques, including DNS and Internet Control Message Protocol (ICMP) tunneling, as a means to bypass traditional security measures [
3,
4]. For example, the SolarWinds Orion supply chain attack exploited DNS tunneling for command-and-control (C2) communication, allowing attackers to exfiltrate data through seemingly benign DNS queries [
5]. These incidents highlight the urgent need to investigate tunneling-based techniques to improve network threat detection and response capabilities.
Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) are essential components of the cloud environment security infrastructure [
6]. These systems continuously monitor network traffic for suspicious activity and known threats, providing a crucial layer of defense against data exfiltration attempts. Among the IDS/IPS tools, Snort (Snort 3.0 is used,
https://www.snort.org, last accessed on 20 December 2025) and Suricata (Suricata 7.0.13 is used,
https://suricata.io/, last accessed on 20 December 2025) are widely recognized for their strong capabilities [
2]. Snort, developed by Cisco, is well-known for its robust packet analysis and logging capabilities. On the other hand, Suricata, developed by the Open Information Security Foundation (OISF), provides advanced multithreading and superior performance in dense-traffic environments.
Despite their widespread use, it is essential to conduct a comprehensive evaluation of Snort and Suricata to detect cloud-specific data exfiltration techniques [
7]. Understanding their effectiveness, detection capabilities, false-positive rates and resource consumption within a cloud environment is crucial for organizations striving to improve their security frameworks. Although both tools have been extensively studied in traditional network settings, their performance in dynamic cloud infrastructures, where traffic patterns and attack vectors vary significantly, requires further investigation.
This study addresses this gap by setting up a controlled cloud environment in which Snort and Suricata are configured to monitor and analyze various data exfiltration methods. Controlled test cases that generate both baseline and exfiltration traffic will be established to capture and compare detection rates, performance, and incidence of false positives. Beyond detection, effective incident response requires forensic capabilities; therefore, we also evaluate tools to analyze exfiltration incidents by integrating the Elasticsearch, Logstash, and Kibana (ELK) stack for advanced data analysis and visualization. This integration enables real-time monitoring, detailed log analysis, and intuitive dashboards, thus enhancing the ability to identify and respond effectively to potential threats. Furthermore, our research evaluates the effectiveness of cloud forensic tools in identifying, analyzing, and mitigating data exfiltration incidents. The method involves identifying a set of cloud forensic tools for data exfiltration analysis and establishing criteria to evaluate them, including ease of use, data recovery capabilities, support for various cloud platforms and the ability to preserve the integrity of digital evidence. Hands-on testing of each tool is performed using controlled scenarios that simulate data exfiltration incidents. The findings contribute to more effective incident response strategies and improved security practices in cloud environments.
In summary, existing studies have evaluated IDS tools under various network configurations. However, a key distinction remains between traditional on-premise evaluations and cloud-based deployments, where factors such as virtualized networking and traffic mirroring fundamentally affect IDS behavior. This study aims to systematically evaluate and compare the detection capabilities of Snort and Suricata, two widely used open-source IDSs, in identifying sophisticated data exfiltration techniques in cloud environments. Specifically, the research addresses the following research questions (RQs):
- RQ0:
How effectively can Snort and Suricata detect ICMP tunneling, a covert communication method often used to bypass traditional security measures?
- RQ1:
What are the detection rates, accuracy, and performance metrics of Snort and Suricata in identifying DNS tunneling using DNSCat2, a tool designed to encapsulate data within DNS queries and responses?
- RQ2:
How do Snort and Suricata perform in detecting DNS tunneling using Iodine, which exploits the NULL resource record type to create stealthy communication channels?
- RQ3:
What are the strengths and limitations of Snort and Suricata regarding detection rates and false positives/negatives across ICMP tunneling, DNSCat2, and Iodine-based attacks?
By addressing these questions, the study seeks to provide actionable insights into optimizing IDS configurations to enhance cloud security and to highlight areas that require further development to combat evolving cyber threats. The organization of this paper is as follows.
Section 2 provides an overview of the tools and technologies used in the study, including detailed descriptions of Snort, Suricata, and the ELK Stack. It also explains DNS tunneling, its role in data exfiltration, and related concepts.
Section 3 reviews existing research on IDS, focusing on Snort and Suricata, as well as other relevant studies on DNS tunneling, ICMP tunneling and cloud security.
Section 4 outlines the experimental setup, including cloud architecture, test scenarios, and detection rules implemented to identify data exfiltration techniques. It also describes the tools and configurations to simulate attacks and monitor traffic. We present the results of experiments comparing the performance of Snort and Suricata in detecting ICMP tunneling, DNS tunneling with DNSCat2, and DNS tunneling with iodine in
Section 5. The section presents performance metrics, including detection rates and false positives, and discusses the results.
Section 6 summarizes the key findings of the study, highlighting the strengths and limitations of Snort and Suricata in cloud environments. The section also provides recommendations to improve detection capabilities and outlines potential areas for future research.
3. Related Work
The work in [
19] addresses the critical challenge of network security, given persistent risks such as phishing, hacking, spyware, and spoofing that compromise data integrity. It reviews various network threats and evaluates open-source security tools, specifically Acunetix (
https://www.acunetix.com, last accessed on 28 July 2025), and IPS, for their effectiveness in mitigating these risks. The key sections of the paper explore security commands, system scan and reconnaissance processes, as well as an analysis of IPS functionality to identify and prevent network vulnerabilities. The findings highlight the limitations of existing tools in fully protecting transmitted data, underscoring the ongoing need for robust network security solutions. The authors of [
20] examined the importance of security in cloud computing environments, where the growing reliance on network-based platforms makes data vulnerable to potential attacks. The work emphasizes the role of NIDS in protecting the availability, confidentiality, and integrity of network systems. Their work analyzes various open-source IDS tools, comparing their features, functionality, and performance to help organizations select the most suitable option for their specific needs. The conclusion emphasizes that while open-source IDS tools vary in their strengths and limitations, they offer flexibility for customization, allowing organizations to customize them to their specific security requirements.
The work in [
21] investigates the impact of the number of active rules on Suricata’s detection accuracy, focusing on Indicators of Compromise (IoC) rules, such as IPRep, HTTP, DNS, MD5 and JA3 [
22]. The analysis evaluates the detection accuracy in five scenarios with varying rule counts, reaching a total of one million rules. This work found a notable decrease in detection accuracy as the number of rules increased, with significant performance drops starting at 100,000 rules in isolated IoC scenarios. In a combined IoC scenario, the detection accuracy decreases as the number of rules per IoC exceeds 10,000, and the performance ultimately degrades to 1 million rules. The study shows that a higher number of activated rules compromises Suricata’s detection accuracy, thereby increasing the risk of cyber attacks by potentially missing known threats. This highlights the need for enhanced defense mechanisms, particularly in cyber threat hunt, to maintain system integrity and detect potential incidents effectively.
The work in [
23] investigates the development and effectiveness of a Suricata-based IPS to improve network security against Distributed Denial of Service (DDoS) attacks, specifically SYN Flood and Ping of Death, within a school network. The waterfall model comprises the phases of analysis, design, implementation, testing, and maintenance. The investigation achieved a detection accuracy of 98% for DDoS threats and 95% for SYN Flood and Ping of Death, resulting in an average detection rate of 96.5% and a low false-positive rate of 2.5%. Implementing IPS stabilized network traffic by preventing excessive malicious requests via IPtables firewall capabilities, demonstrating robust, reliable security against common DDoS attacks. This study highlights the efficacy of systematically deploying IPS to protect network integrity in educational institutions.
The authors of [
24] emphasize the importance of intrusion detection in securing cloud computing environments, which are highly susceptible to cyber attacks due to their dependence on Internet connectivity. The authors propose an IDS for cloud platforms that integrates signature-based and anomaly-based detection to identify both known and unknown threats. Using a hybrid detection mechanism at the Cloud Hypervisor level that leverages K-Nearest Neighbors (KNN) and Support Vector Machine (SVM) algorithms, the study demonstrates that the SVM-based model achieves higher accuracy than prior models. This approach aims to enhance security and reliability in cloud computing by dynamically detecting deviations from normal activities as potential intrusions. The work in [
25] analyzes the effectiveness of two widely used NIDS, Snort and Suricata, in addressing the growing complexity of cyber threats. It examines the architectural foundations, detection features, and performance metrics of each system, concentrating on its strengths and limitations in various network environments. Snort’s extensive rule-based detection and customization make it suitable for settings requiring specific threat detection; however, its lack of multithreading limits its performance in high-traffic scenarios. Suricata, on the other hand, employs multithreading to handle high-throughput traffic and large datasets, which makes it well suited to dynamic environments. It also supports protocol anomaly detection and file inspection. The study highlights the crucial role of continuous improvement in NIDS, including the integration of machine learning and AI to enhance threat prediction and adaptability. Although Snort and Suricata each offer unique benefits, their applicability ultimately depends on organizational needs, network demands, and security strategies.
The work in [
26] examines the security challenges posed by the Internet of Things (IoT), in which unprecedented connectivity amplifies vulnerability to cyber threats. Focusing on Snort as an NIDS, the paper analyzes its architecture, rule customization, and effectiveness in securing IoT environments. Key issues in IoT security include resource constraints, varied communication protocols, and the need for tailored defense mechanisms. The experimental results highlight Snort’s efficiency in detecting malicious activity while maintaining low memory and CPU usage, and it outperforms other NIDS tools, such as Wazuh (
https://wazuh.com, last accessed on 18 June 2025), and Suricata. The findings underscore the importance of advanced tools such as Snort for addressing IoT-specific threats and emphasize practical strategies, including network segmentation and continuous monitoring, to strengthen network defenses. As IoT ecosystems become increasingly complex, Snort’s proactive threat-detection capabilities provide a robust, resource-efficient solution to enhance network resilience.
The research in [
27] addresses the growing threat of botnet-driven cyberattacks, which is exacerbated by advances in AI and the increasing shift of organizations to cloud-based environments. Botnets are intended to disrupt services, steal credentials, or gain unauthorized network access, presenting significant challenges for network security professionals. The study proposes a new model to detect and mitigate botnet traffic in cloud environments by integrating IDS and SIEM systems. The model successfully detected and logged botnet attacks through this setup, enabling the generation of detailed reports to analyze attack characteristics, such as traffic volume and source IP addresses. The conclusion highlights that the model effectively supports network security analysts by providing a comprehensive view of attack data, facilitating proactive threat management. Future enhancements could include the deployment of firewalls and a demilitarized zone (DMZ) to improve filtering and segmentation, respectively, thereby strengthening network defenses. This model demonstrates a viable strategy for identifying and countering botnet attacks, providing network security professionals with a robust set of tools to protect cloud-based infrastructure.
Table 1 introduces the thematic organization of some related works in IDS for cloud computing environments. To this end, our review of the existing literature highlights gaps in the comprehensive examination of Snort and Suricata in cloud environments. Hence, our article provides a comparative evaluation of Snort and Suricata for detecting data exfiltration tunnels in cloud environments.
6. Conclusions and Future Work
The main contribution of this paper is an empirical, cloud-agnostic evaluation of Snort and Suricata for detecting covert data exfiltration via DNS and ICMP tunneling. This paper aimed to evaluate the effectiveness of Snort and Suricata in detecting a set of covert data exfiltration techniques in a cloud environment, with a focus on ICMP and DNS tunneling scenarios. This comparison showed distinct performance differences between these two IDSs. Suricata consistently outperformed Snort in DNS-based tunneling detection, achieving full Recall in both DNSCat2 and Iodine, whereas Snort’s Recall remained considerably lower at 85.7% and 66.7%, respectively. In contrast, both tools failed to detect ICMP tunneling generated by Metasploit and reported 0% Recall, highlighting the limitations of a default signature-based configuration for addressing sophisticated tunneling mechanisms. The results underscore the need to refine rule sets, develop signature-based methods, and integrate behavior analytics to address shortcomings that a traditional pattern-matching approach cannot resolve. Given the wide variety of rule libraries available, the rapidly changing threat landscape of covert exfiltration techniques, and the lack of standardized testing frameworks for IDS/IPS platforms, more systematic large-scale testing is necessary to establish performance boundaries across diverse operational environments. When properly tuned and integrated into a centralized logging infrastructure such as ELK, both Snort and Suricata can continue to provide valuable capabilities to enhance intrusion detection, improve network visibility, and support digital forensics investigations in cloud environments.
It should be noted that although the experiments were conducted on AWS, the observed detection behavior of Snort and Suricata is not tied to AWS-specific features and is expected to generalize to other cloud environments that employ virtualized networking, traffic mirroring, and comparable workload characteristics.
The future research directions of this article are as follows:
Custom Rule Development. For ICMP tunneling, additional rules should be developed to detect anomalies, such as considerable ICMP payloads, high-frequency ICMP traffic, or specific byte patterns indicative of tunneling.
Continuous Tuning. Regular updates to rule sets are necessary to adapt to evolving tunneling techniques and ensure consistent detection performance.
Integration with Advanced Tools. Combining Snort and Suricata with machine learning-based anomaly detection systems can enhance their ability to detect sophisticated threats, such as ICMP tunneling.
Further Testing. Future work will focus on large-scale experimental evaluation that involves more tunneling scenarios and repeated trials to enable statistically meaningful analysis, including systematic parameter variation, higher traffic volumes, and the integration of additional tunneling tools and protocols. These enhancements aim to improve the statistical robustness and generalizability of the findings.