Identifying abnormal pattern in cellular communication flows

in Proceedings of IPTComm 2013 (2013, October)

Analyzing communication flows on the network can help to improve the overall quality it provides to its users and allow the operators to detect abnormal patterns and react accordingly. In this paper we ... [more ▼]

Analyzing communication flows on the network can help to improve the overall quality it provides to its users and allow the operators to detect abnormal patterns and react accordingly. In this paper we consider the analysis of large volumes of cellular communications records. We propose a method that detects abnormal communications events covering call data record volumes, comprising a country-level data set. We detect patterns by calculating a weighted average using a sliding window with a fixed period and correlate the results with actual events happening at that time. We are able to successfully detect several events using a data set provided by a mobile phone operator, and suggest examples of future usage of the outcome such as real time pattern detection and possible visualisation for mobile phone operators. [less ▲]

Advanced Detection Tool for PDF Threats

in Proceedings of the sixth International Workshop on Autonomous and Spontaneous Security, RHUL, Egham, U.K., 12th-13th September 2013 (2013, September 13)

In this paper we introduce an efficient application for malicious PDF detection: ADEPT. With targeted attacks rising over the recent past, exploring a new detection and mitigation paradigm becomes ... [more ▼]

In this paper we introduce an efficient application for malicious PDF detection: ADEPT. With targeted attacks rising over the recent past, exploring a new detection and mitigation paradigm becomes mandatory. The use of malicious PDF files that exploit vulnerabilities in well-known PDF readers has become a popular vector for targeted at- tacks, for which few efficient approaches exist. Although simple in theory, parsing followed by analysis of such files is resource-intensive and may even be impossible due to several obfuscation and reader-specific artifacts. Our paper describes a new approach for detecting such malicious payloads that leverages machine learning techniques and an efficient feature selection mechanism for rapidly detecting anomalies. We assess our approach on a large selection of malicious files and report the experimental performance results for the developed prototype. [less ▲]

ASMATRA: Ranking ASs Providing Transit Service to Malware Hosters

in IFIP/IEEE International Symposium on Integrated Network Management IM2013 (2013)

The Internet has grown into an enormous network offering a variety of services, which are spread over a multitude of domains. BGP-routing and Autonomous Systems (AS) are the key components for maintaining ... [more ▼]

The Internet has grown into an enormous network offering a variety of services, which are spread over a multitude of domains. BGP-routing and Autonomous Systems (AS) are the key components for maintaining high connectivity in the Internet. Unfortunately, Internet Service Providers (ISPs) operating ASs do not only host normal users and content, but also malicious content used by attackers for spreading malware, hosting phishing web-sites or performing any kind of fraudulent activity. Practical analysis shows that such malware-providing ASs prevent themselves from being de-peered by hiding behind other ASs, which do not host the malware themselves but simply provide transit service for malware. This paper presents a new method for detecting ASs that provide transit service for malware hosters, without being malicious themselves. A formal definition of the problem and the metrics are determined by using the AS graph. The PageRank algorithm is applied to improve the scalability and the completeness of the approach. The method is assessed on real and publicly available datasets, showing promising results. [less ▲]

Proactive Discovery of Phishing Related Domain Names

in Proceedings of the 15th International Symposium on Research in Attacks, Intrusions and Defenses, Amsterdam 12-14 September 2012 (2012, September)

Phishing is an important security issue to the Internet, which has a significant economic impact. The main solution to counteract this threat is currently reactive blacklisting; however, as phishing ... [more ▼]

Phishing is an important security issue to the Internet, which has a significant economic impact. The main solution to counteract this threat is currently reactive blacklisting; however, as phishing attacks are mainly performed over short periods of time, reactive methods are too slow. As a result, new approaches to early identify malicious websites are needed. In this paper a new proactive discovery of phishing related domain names is introduced. We mainly focus on the automated detec- tion of possible domain registrations for malicious activities. We leverage techniques coming from natural language modelling in order to build pro- active blacklists. The entries in this list are built using language models and vocabularies encountered in phishing related activities - “secure”, “banking”, brand names, etc. Once a pro-active blacklist is created, ongoing and daily monitoring of only these domains can lead to the efficient detection of phishing web sites. [less ▲]

A Distance-Based Method to Detect Anomalous Attributes in Log Files

in Proceedings of IEEE/IFIP NOMS 2012 (2012, April)

Dealing with large volumes of logs is like the prover- bial needle in the haystack problem. Finding relevant events that might be associated with an incident, or real time analysis of operational logs is ... [more ▼]

Dealing with large volumes of logs is like the prover- bial needle in the haystack problem. Finding relevant events that might be associated with an incident, or real time analysis of operational logs is extremely difficult when the underlying data volume is huge and when no explicit misuse model exists. While domain-specific knowledge and human expertise may be useful in analysing log data, automated approaches for detecting anomalies and track incidents are the only viable solutions when confronted with large volumes of data. In this paper we address the issue of automated log analysis and consider more specifically the case of ISP-provided firewall logs. We leverage approaches derived from statistical process control and information theory in order to track potential incidents and detect suspicious network activity. [less ▲]

Instant Degradation of Anonymity in Low-Latency Anonymisation Systems

in Sadre, Ramin; Novotny, Jiri; Celeda, Pavel (Eds.) et al Dependable Networks and Services, LNCS 7279 (2012)

Measuring anonymity using network coordinate systems

in International Symposium on Communications and Information Technologies (ISCIT), 2011 (2011)

Popularity and awareness of anonymisation systems increased tremendously over the past years, however only a very few systems made it from research to production. These systems usually add intermediate ... [more ▼]

Popularity and awareness of anonymisation systems increased tremendously over the past years, however only a very few systems made it from research to production. These systems usually add intermediate nodes in the communication path aiming to hide user identities. Several attacks against these systems exist, like timing attacks or exploitation of latency information. In this paper, we propose an alternative approach to disclose users of current popular anonymisation systems in practice by the means of virtual network coordinate systems, a widely accepted method for latency prediction and network optimisation. Mapping physical nodes to a n-dimensional space can reveal a geographical proximity that is used to disclose users, who expect to stay anonymous. We define a model that leverages network coordinates in order to measure quantitatively the anonymity services and evaluate it on the Planet-Lab research network. The basic idea is to analyse the relative distance between nodes and to calculate the probability of nodes being hosted in the same location. Evaluation proves that our proposed model can be used as a measure of anonymity. [less ▲]

Machine Learning Techniques for Passive Network Inventory

in IEEE Transactions on Network and Service Management (2010), 7(4), 244-257

Being able to fingerprint devices and services, i.e., remotely identify running code, is a powerful service for both security assessment and inventory management. This paper describes two novel ... [more ▼]

Being able to fingerprint devices and services, i.e., remotely identify running code, is a powerful service for both security assessment and inventory management. This paper describes two novel fingerprinting techniques supported by isomorphic based distances which are adapted for measuring the similarity between two syntactic trees. The first method leverages the support vector machines paradigm and requires a learning stage. The second method operates in an unsupervised manner thanks to a new classification algorithm derived from the ROCK and QROCK algorithms. It provides an efficient and accurate classification. We highlight the use of such classification techniques for identifying the remote running applications. The approaches are validated through extensive experimentations on SIP (Session Initiation Protocol) for evaluating the impact of the different parameters and identifying the best configuration before applying the techniques to network traces collected by a real operator. [less ▲]

Abusing SIP authentication

in Journal of Information Assurance and Security (2009), 4

The recent and massive deployment of Voice over IP infrastructures had raised the importance of the VoIP security and more precisely of the underlying signalisation protocol SIP. In this paper, we will ... [more ▼]

The recent and massive deployment of Voice over IP infrastructures had raised the importance of the VoIP security and more precisely of the underlying signalisation protocol SIP. In this paper, we will present a new attack against the authentication mechanism of SIP. This attack allows to perform toll fraud and call hijacking. We will detail the formal specification method that allowed to detect this vulnerability, highlight a simple usage case and propose a mitigation technique. [less ▲]

Using Game Theory to configure P2P SIP

in Lecture Notes in Computer Science (2009)