Open Access
Mejoras en la identificación de tráfico de aplicación basado en firmas
(2008) Santolaya Bea, Néstor; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
Traffic identification has been based traditionally on transport protocol ports, associating always the same ports with the same applications. Nowadays that assumption is not true and new methods like signature identification or statistical techniques are applied. This work presents a method based on signature identification with some improvements. The use of regular expressions for typical applications has been studied deeply and its use has been improved in the aspects of percentage identification and resources consumption. On the other hand, a flows-record structure has been applied in order to classify those packets that do not verify any regular expression. Results are compared with the opensource related project L7-filter, and the improvements are presented. Finally, detailed regular expressions for analyzed applications are included in the paper, especially P2P applications.
Open Access
On the reduction of authoritative DNS cache timeouts: detection and implications for user privacy
(Elsevier, 2021) Hernández Quintanilla, Tomás; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The domain name system (DNS) is an Internet network service that is used by hosts to resolve IP addresses from symbolic names. This basic service has been attacked and abused many times, as it is one of the oldest and most vulnerable services on the Internet. Some DNS resolvers conduct DNS manipulation, in which authoritative DNS responses are modified. This DNS manipulation is sometimes used for legitimate reasons (e.g., parental control) and other times is used to support malicious activities, such as DNS poisoning or data collection. Between these DNS manipulation activities, some Internet service providers (ISPs) are changing the DNS cache timeout of the DNS responses with which their DNS resolvers responded to obtain additional data about their subscribers. These data can be a detailed web browsing profile of the user. This approach does not require a large investment and can yield huge benefits if the information is used or sold. Therefore, user privacy is disputed. We conducted a study in which we analyse how ISPs use this DNS manipulation, propose a method for identifying this DNS manipulation by the end-user and determine the amount of information an ISP can collect by using it. We also developed a public web tool, for which the source code is available, that can help Internet users determine whether their privacy is being compromised by their ISP via the exploitation of DNS cache timeouts. This service can facilitate the collection of data on how many people are victims of this abuse and which ISPs around the world are utilizing this technique.
Open Access
Ransomware early detection by the analysis of file sharing traffic
(Elsevier, 2018) Morató Osés, Daniel; Berrueta Irigoyen, Eduardo; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Crypto ransomware is a type of malware that locks access to user files by encrypting them and demands a ransom in order to obtain the decryption key. This type of malware has become a serious threat for most enterprises. In those cases where the infected computer has access to documents in network shared volumes, a single host can lock access to documents across several departments in the company. We propose an algorithm that can detect ransomware action and prevent further activity over shared documents. The algorithm is based on the analysis of passively monitored traffic by a network probe. 19 different ransomware families were used for testing the algorithm in action. The results show that it can detect ransomware activity in less than 20 s, before more than 10 files are lost. Recovery of even those files was also possible because their content was stored in the traffic monitored by the network probe. Several days of traffic from real corporate networks were used to validate a low rate of false alarms. This paper offers also analytical models for the probability of early detection and the probability of false alarms for an arbitrarily large population of users.
Open Access
Detección de congestión en la Internet europea
(IEEE, 2007) Hernández, Ana; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
In this paper we present a study about the utilization of one-way delay measurements to detect and characterize network congestion in the european Internet. The experiments have been made using the ETOMIC platfom that allows one-way delay measurement with high precision timestamps. We have found a peculiar router behaviour in which the bottleneck is not the available bandwidth but it is the packet processing power of the router (backplane and CPU constraints). This router has been characterized with several network parameters. Some of them are the dependency of this limitation with the input data rate in packets per second, the size of burst packet losses measured in packets or time and the absence of specific scheduling algorithms in the router that could affect to larger flows.
Open Access
Crypto-ransomware detection using machine learning models in file-sharing network scenarios with encrypted traffic
(Elsevier, 2022) Berrueta Irigoyen, Eduardo; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Ransomware is considered as a significant threat for home users and enterprises. In corporate scenarios, users’ computers usually store only system and program files, while all the documents are accessed from shared servers. In these scenarios, one crypto-ransomware infected host is capable of locking the access to all shared files it has access to, which can be the whole set of files from a workgroup of users. We propose a tool to detect and block crypto-ransomware activity based on file-sharing traffic analysis. The tool monitors the traffic exchanged between the clients and the file servers and using machine learning techniques it searches for patterns in the traffic that betray ransomware actions while reading and overwriting files. This is the first proposal designed to work not only for clear text protocols but also for encrypted file-sharing protocols. We extract features from network traffic that describe the activity opening, closing, and modifying files. The features allow the differentiation between ransomware activity and high activity from benign applications. We train and test the detection model using a large set of more than 70 ransomware binaries from 33 different strains and more than 2,400 h of ‘not infected’ traffic from real users. The results reveal that the proposed tool can detect all ransomware binaries described, including those not used in the training phase. This paper provides a validation of the algorithm by studying the false positive rate and the amount of information from user files that the ransomware could encrypt before being detected
Open Access
Evaluation of RTT as an estimation of interactivity time for QoE evaluation in remote desktop environments
(IEEE, 2023) Arellano Usón, Jesús; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
In recent years, there has been a notable surge in the utilization of remote desktop services, largely driven by the emergence of new remote work models introduced during the pandemic. Traditional evaluation of the quality of experience (QoE) of users in remote desktop environments has relied on measures such as round-trip time (RTT). However, these measures are insufficient to capture all the factors that influence QoE. This study evaluated RTT and interactivity time in an enterprise environment over a period of 6 months and analysed the suitability of using RTT drawing previously unexplored connections between RTT, interactivity, and QoE. The results indicate that RTT is an insufficient indicator of QoE in productive environments with low RTT values. We outline some precise measures of interactivity needed to capture all the factors that contribute to QoE in remote desktop environments.
Open Access
Techniques for better alias resolution in Internet topology discovery
(IEEE, 2009) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta Konputazioa
One of the challenging problems related with network topology discovery in Internet is the process of IP address alias identification. Topology information is usually obtained from a set of traceroutes that provide IP addresses of routers in the path from a source to a destination. If these traceroutes are repeated between several source/destination pairs we can get a sampling of all IP addresses for crossed routers. In order to generate the topology graph in which each router is a node, it is needed to identify all IP addresses that belong to the same router. In this work we propose improvements over existing methods to obtain alias identification related mainly with the types and options in probing packets.
Open Access
High-speed analysis of SMB2 file sharing traffic without TCP stream reconstruction
(IEEE, 2019) Berrueta Irigoyen, Eduardo; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This paper presents a file sharing traffic analysis methodology for Server Message Block (SMB), a common protocol in the corporate environment. The design is focused on improving the traffic analysis rate that can be obtained per CPU core in the analysis machine. SMB is most commonly transported over Transmission Control Protocol (TCP) and therefore its analysis requires TCP stream reconstruction. We evaluate a traffic analysis design which does not require stream reconstruction. We compare the results obtained to a reference full reconstruction analysis, both in accuracy of the measurements and maximum rate per CPU core. We achieve an increment of 30% in the traffic processing rate, at the expense of a small loss in accuracy computing the probability distribution function for the protocol response times.
Open Access
Traffic generator using Perlin Noise
(IEEE, 2012) Prieto Suárez, Iria; Izal Azcárate, Mikel; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Study of high speed networks such as optical next generation burst or packet switched networks require large amounts of synthetic traffic to feed simulators. Methods to generate self-similar long range dependent traffic already exist but they usually work by generating large blocks of traffic of fixed time duration. This limits simulated time or require very high amount of data to be stored before simulation. On this work it is shown how self-similar traffic can be generated using Perlin Noise, an algorithm commonly used to generate 2D/3D noise for natural looking graphics. 1-dimension Perlin Noise can be interpreted as network traffic and used to generate long range dependent traffic for network simulation. The algorithm is compared to more classical approach Random Midpoint Displacement showing at traffic generated is similar but can be generated continuously with no fixed block size.
Open Access
A popularity-aware method for discovering server IP addresses related to websites
(IEEE, 2013) Torres García, Luis Miguel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
The complexity of web traffic has grown in the past years as websites evolve and new services are provided over the HTTP protocol. When accessing a website, multiple connections to different servers are opened and it is usually difficult to distinguish which servers are related to which sites. However, this information is useful from the perspective of security and accounting and can also help to label web traffic and use it as ground truth for traffic classification systems. In this paper we present a method to discover server IP addresses related to specific websites in a traffic trace. Our method uses NetFlow-type records which makes it scalable and impervious to encryption of packet payloads. It is, moreover, popularity-aware in the sense that it takes into consideration the differences in the number of accesses to each site in order to provide a better identification of servers. The method can be used to gather data from a group of interesting websites or, by applying it to a representative set of websites, it can label a sizeable number of connections in a packet trace.