177 research outputs found

    A survey of defense mechanisms against distributed denial of service (DDOS) flooding attacks

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    Distributed Denial of Service (DDoS) flooding attacks are one of the biggest concerns for security professionals. DDoS flooding attacks are typically explicit attempts to disrupt legitimate users' access to services. Attackers usually gain access to a large number of computers by exploiting their vulnerabilities to set up attack armies (i.e., Botnets). Once an attack army has been set up, an attacker can invoke a coordinated, large-scale attack against one or more targets. Developing a comprehensive defense mechanism against identified and anticipated DDoS flooding attacks is a desired goal of the intrusion detection and prevention research community. However, the development of such a mechanism requires a comprehensive understanding of the problem and the techniques that have been used thus far in preventing, detecting, and responding to various DDoS flooding attacks. In this paper, we explore the scope of the DDoS flooding attack problem and attempts to combat it. We categorize the DDoS flooding attacks and classify existing countermeasures based on where and when they prevent, detect, and respond to the DDoS flooding attacks. Moreover, we highlight the need for a comprehensive distributed and collaborative defense approach. Our primary intention for this work is to stimulate the research community into developing creative, effective, efficient, and comprehensive prevention, detection, and response mechanisms that address the DDoS flooding problem before, during and after an actual attack. © 1998-2012 IEEE

    Distributed reflection denial of service attack: A critical review

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    As the world becomes increasingly connected and the number of users grows exponentially and “things” go online, the prospect of cyberspace becoming a significant target for cybercriminals is a reality. Any host or device that is exposed on the internet is a prime target for cyberattacks. A denial-of-service (DoS) attack is accountable for the majority of these cyberattacks. Although various solutions have been proposed by researchers to mitigate this issue, cybercriminals always adapt their attack approach to circumvent countermeasures. One of the modified DoS attacks is known as distributed reflection denial-of-service attack (DRDoS). This type of attack is considered to be a more severe variant of the DoS attack and can be conducted in transmission control protocol (TCP) and user datagram protocol (UDP). However, this attack is not effective in the TCP protocol due to the three-way handshake approach that prevents this type of attack from passing through the network layer to the upper layers in the network stack. On the other hand, UDP is a connectionless protocol, so most of these DRDoS attacks pass through UDP. This study aims to examine and identify the differences between TCP-based and UDP-based DRDoS attacks

    An Accountability Architecture for the Internet

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    In the current Internet, senders are not accountable for the packets they send. As a result, malicious users send unwanted traffic that wastes shared resources and degrades network performance. Stopping such attacks requires identifying the responsible principal and filtering any unwanted traffic it sends. However, senders can obscure their identity: a packet identifies its sender only by the source address, but the Internet Protocol does not enforce that this address be correct. Additionally, affected destinations have no way to prevent the sender from continuing to cause harm. An accountable network binds sender identities to packets they send for the purpose of holding senders responsible for their traffic. In this dissertation, I present an accountable network-level architecture that strongly binds senders to packets and gives receivers control over who can send traffic to them. Holding senders accountable for their actions would prevent many of the attacks that disrupt the Internet today. Previous work in attack prevention proposes methods of binding packets to senders, giving receivers control over who sends what to them, or both. However, they all require trusted elements on the forwarding path, to either assist in identifying the sender or to filter unwanted packets. These elements are often not under the control of the receiver and may become corrupt. This dissertation shows that the Internet architecture can be extended to allow receivers to block traffic from unwanted senders, even in the presence of malicious devices in the forwarding path. This dissertation validates this thesis with three contributions. The first contribution is DNA, a network architecture that strongly binds packets to their sender, allowing routers to reject unaccountable traffic and recipients to block traffic from unwanted senders. Unlike prior work, which trusts on-path devices to behave correctly, the only trusted component in DNA is an identity certification authority. All other entities may misbehave and are either blocked or evicted from the network. The second contribution is NeighborhoodWatch, a secure, distributed, scalable object store that is capable of withstanding misbehavior by its constituent nodes. DNA uses NeighborhoodWatch to store receiver-specific requests block individual senders. The third contribution is VanGuard, an accountable capability architecture. Capabilities are small, receiver-generated tokens that grant the sender permission to send traffic to receiver. Existing capability architectures are not accountable, assume a protected channel for obtaining capabilities, and allow on-path devices to steal capabilities. VanGuard builds a capability architecture on top of DNA, preventing capability theft and protecting the capability request channel by allowing receivers to block senders that flood the channel. Once a sender obtains capabilities, it no longer needs to sign traffic, thus allowing greater efficiency than DNA alone. The DNA architecture demonstrates that it is possible to create an accountable network architecture in which none of the devices on the forwarding path must be trusted. DNA holds senders responsible for their traffic by allowing receivers to block senders; to store this blocking state, DNA relies on the NeighborhoodWatch DHT. VanGuard extends DNA and reduces its overhead by incorporating capabilities, which gives destinations further control over the traffic that sources send to them

    A Framework for anonymous background data delivery and feedback

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    The current state of the industry’s methods of collecting background data reflecting diagnostic and usage information are often opaque and require users to place a lot of trust in the entity receiving the data. For vendors, having a centralized database of potentially sensitive data is a privacy protection headache and a potential liability should a breach of that database occur. Unfortunately, high profile privacy failures are not uncommon, so many individuals and companies are understandably skeptical and choose not to contribute any information. It is a shame, since the data could be used for improving reliability, or getting stronger security, or for valuable academic research into real-world usage patterns. We propose, implement and evaluate a framework for non-realtime anonymous data collection, aggregation for analysis, and feedback. Departing from the usual “trusted core” approach, we aim to maintain reporters’ anonymity even if the centralized part of the system is compromised. We design a peer-to-peer mix network and its protocol that are tuned to the properties of background diagnostic traffic. Our system delivers data to a centralized repository while maintaining (i) source anonymity, (ii) privacy in transit, and (iii) the ability to provide analysis feedback back to the source. By removing the core’s ability to identify the source of data and to track users over time, we drastically reduce its attractiveness as a potential attack target and allow vendors to make concrete and verifiable privacy and anonymity claims

    An Inter-domain Collaboration Scheme to Remedy DDoS Attacks in Computer Networks

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    Distributed Denial-of-Service (DDoS) attacks continue to trouble network operators and service providers, and with increasing intensity. Effective response to DDoS can be slow (because of manual diagnosis and interaction) and potentially self-defeating (as indiscriminate filtering accomplishes a likely goal of the attacker), and this is the result of the discrepancy between the service provider's flow-based, application-level view of traffic and the network operator's packet-based, network-level view and limited functionality. Furthermore, a network required to take action may be in an Autonomous System (AS) several AS-hops away from the service, so it has no direct relationship with the service on whose behalf it acts. This paper presents Antidose, a means of interaction between a vulnerable peripheral service and an indirectly related AS that allows the AS to confidently deploy local filtering with discrimination under the control of the remote service. We implement the core filtering mechanism of Antidose, and provide an analysis of it to demonstrate that conscious attacks against the mechanism will not expose the AS to additional attacks. We present a performance evaluation to show that the mechanism is operationally feasible in the emerging trend of operators' willingness to increase the programmability of their hardware with SDN technologies such as OpenFlow, as well as to act to mitigate attacks on downstream customers

    Investigation of open resolvers in DNS reflection DDoS attacks

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    Les serveurs du système de noms de domaine (DNS) représentent des éléments clés des réseaux Internet. Récemment, les attaquants ont profité de ce service pour lancer des attaques massives de déni de service distribué (DDoS) contre de nombreuses organisations [1, 2, 3]. Ceci est rendu possible grâce aux différentes vulnérabilités liées à la conception, implantation ou une mauvaise configuration du protocole DNS. Les attaques DDoS amplifiées par DNS sont des menaces dangereuses pour les utilisateurs d’Internet. L’objectif de cette étude est d’acquérir une meilleure compréhension des attaques DDoS amplifiées par DNS par l’investigation des résolveurs DNS ouverts à travers le monde. Dans ce contexte, il est nécessaire d’adopter une approche en phase précoce pour détecter les résolveurs DNS ouverts. Cela devient cruciale dans le processus d’enquête. Dans cette thèse, nous nous intéresserons à l’utilisation de résolveurs DNS ouverts dans les attaques DDoS amplifiées par DNS. Plus précisément, la principale contribution de notre recherche est la suivante : (i) Nous profilons les résolveurs DNS ouverts, ce qui implique : détecter les résolveurs ouverts, les localiser, détecter leur système d’exploitation et le type de leur connectivité, et étudier le but de leur vivacité. (ii) Nous effectuons une évaluation de la sécurité des résolveurs DNS ouverts et leurs vulnérabilités. De plus, nous discutons les fonctions de sécurité des résolveurs DNS, qui fournissent, par inadvertence, les attaquants par la capacité d’effectuer des attaques DDoS amplifiées par DNS. (iii) Nous présentons une analyse pour démontrer l’association des résolveurs DNS ouverts avec les menaces de logiciels malveillants.Domain Name System (DNS) servers represent key components of Internet networks. Recently, attackers have taken advantage of this service to launch massive Distributed Denial of Service (DDoS) attacks against numerous organizations [1, 2, 3]. This is made possible due to the various vulnerabilities linked to the design, implementation or misconfiguration of the DNS protocol. DNS reflection DDoS attacks are harmful threats for internet users. The goal of this study is to gain a better understanding of DNS reflection DDoS attacks through the investigation of DNS open resolvers around the world. In this context, there is a need for an early phase approach to detect and fingerprint DNS open resolvers. This becomes crucial in the process of investigation. In this thesis, we elaborate on the usage of DNS open resolvers in DNS reflection DDoS attacks. More precisely, the main contribution of our research is as follows : (i) We profile DNS open resolvers, which involves : detecting open resolvers, locating them, fingerprinting their operating system, fingerprinting the type of their connectivity, studying the purpose of their liveness. (ii) We conduct an assessment with respect to DNS open resolvers security and their vulnerabilities. Moreover, we discuss the security features that DNS open resolvers are equipped with, which inadvertently provide the capability to the attackers in order to carry out DNS reflection DDoS attacks. (iii) We present an analysis to demonstrate the association of DNS open resolvers with malware threats

    AnNotify: A Private Notification Service

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    AnNotify is a scalable service for private, timely and low-cost online notifications, based on anonymous communication, sharding, dummy queries, and Bloom filters. We present the design and analysis of AnNotify, as well as an evaluation of its costs. We outline the design of AnNotify and calculate the concrete advantage of an adversary observing multiple queries. We present a number of extensions, such as generic presence and broadcast notifications, and applications, including notifications for incoming messages in anonymous communications, updates to private cached web and Domain Name Service (DNS) queries

    Towards Coordinated, Network-Wide Traffic Monitoring for Early Detection of DDoS Flooding Attacks

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    DDoS flooding attacks are one of the biggest concerns for security professionals and they are typically explicit attempts to disrupt legitimate users' access to services. Developing a comprehensive defense mechanism against such attacks requires a comprehensive understanding of the problem and the techniques that have been used thus far in preventing, detecting, and responding to various such attacks. In this thesis, we dig into the problem of DDoS flooding attacks from four directions: (1) We study the origin of these attacks, their variations, and various existing defense mechanisms against them. Our literature review gives insight into a list of key required features for the next generation of DDoS flooding defense mechanisms. The most important requirement on this list is to see more distributed DDoS flooding defense mechanisms in near future, (2) In such systems, the success in detecting DDoS flooding attacks earlier and in a distributed fashion is highly dependent on the quality and quantity of the traffic flows that are covered by the employed traffic monitoring mechanisms. This motivates us to study and understand the challenges of existing traffic monitoring mechanisms, (3) We propose a novel distributed, coordinated, network-wide traffic monitoring (DiCoTraM) approach that addresses the key challenges of current traffic monitoring mechanisms. DiCoTraM enhances flow coverage to enable effective, early detection of DDoS flooding attacks. We compare and evaluate the performance of DiCoTraM with various other traffic monitoring mechanisms in terms of their total flow coverage and DDoS flooding attack flow coverage, and (4) We evaluate the effectiveness of DiCoTraM with cSamp, an existing traffic monitoring mechanism that outperforms most of other traffic monitoring mechanisms, with regards to supporting early detection of DDoS flooding attacks (i.e., at the intermediate network) by employing two existing DDoS flooding detection mechanisms over them. We then compare the effectiveness of DiCoTraM with that of cSamp by comparing the detection rates and false positive rates achieved when the selected detection mechanisms are employed over DiCoTraM and cSamp. The results show that DiCoTraM outperforms other traffic monitoring mechanisms in terms of DDoS flooding attack flow coverage
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