An SDN-based Approach For Defending Against Reflective DDoS Attacks

Distributed Reflective Denial of Service (DRDoS) attacks are an immanent threat to Internet services. The potential scale of such attacks became apparent in March 2018 when a memcached-based attack peaked at 1.7 Tbps. Novel services built upon UDP increase the need for automated mitigation mechanisms that react to attacks without prior knowledge of the actual application protocols used. With the flexibility that software-defined networks offer, we developed a new approach for defending against DRDoS attacks; it not only protects against arbitrary DRDoS attacks but is also transparent for the attack target and can be used without assistance of the target host operator. The approach provides a robust mitigation system which is protocol-agnostic and effective in the defense against DRDoS attacks

PROVIDE: hiding from automated network scans with proofs of identity

Network scanners are a valuable tool for researchers and administrators, however they are also used by malicious actors to identify vulnerable hosts on a network. Upon the disclosure of a security vulnerability, scans are launched within hours. These opportunistic attackers enumerate blocks of IP addresses in hope of discovering an exploitable host. Fortunately, defensive measures such as port knocking protocols (PKPs) allow a service to remain stealth to unauthorized IP addresses. The service is revealed only when a client includes a special authentication token (AT) in the IP/TCP header. However this AT is generated from a secret shared between the clients/servers and distributed manually to each endpoint. As a result, these defense measures have failed to be widely adopted by other protocols such as HTTP/S due to challenges in distributing the shared secrets. In this paper we propose a scalable solution to this problem for services accessed by domain name. We make the following observation: automated network scanners access servers by IP address, while legitimate clients access the server by name. Therefore a service should only reveal itself to clients who know its name. Based on this principal, we have created a proof of the verifier’s identity (a.k.a. PROVIDE) protocol that allows a prover (legitimate user) to convince a verifier (service) that it is knowledgeable of the verifier’s identity. We present a PROVIDE implementation using a PKP and DNS (PKP+DNS) that uses DNS TXT records to distribute identification tokens (IDT) while DNS PTR records for the service’s domain name are prohibited to prevent reverse DNS lookups. Clients are modified to make an additional DNS TXT query to obtain the IDT which is used by the PKP to generate an AT. The inclusion of an AT in the packet header, generated from the DNS TXT query, is proof the client knows the service’s identity. We analyze the effectiveness of this mechanism with respect to brute force attempts for various strength ATs and discuss practical considerations.This work has been supported by the National Science Foundation (NSF) awards #1430145, #1414119, and #1012798

DDoS-Capable IoT Malwares: comparative analysis and Mirai Investigation

The Internet of Things (IoT) revolution has not only carried the astonishing promise to interconnect a whole generation of traditionally “dumb” devices, but also brought to the Internet the menace of billions of badly protected and easily hackable objects. Not surprisingly, this sudden flooding of fresh and insecure devices fueled older threats, such as Distributed Denial of Service (DDoS) attacks. In this paper, we first propose an updated and comprehensive taxonomy of DDoS attacks, together with a number of examples on how this classification maps to real-world attacks. Then, we outline the current situation of DDoS-enabled malwares in IoT networks, highlighting how recent data support our concerns about the growing in popularity of these malwares. Finally, we give a detailed analysis of the general framework and the operating principles of Mirai, the most disruptive DDoS-capable IoT malware seen so far

Towards Loop-Free Forwarding of Anonymous Internet Datagrams that Enforce Provenance

The way in which addressing and forwarding are implemented in the Internet constitutes one of its biggest privacy and security challenges. The fact that source addresses in Internet datagrams cannot be trusted makes the IP Internet inherently vulnerable to DoS and DDoS attacks. The Internet forwarding plane is open to attacks to the privacy of datagram sources, because source addresses in Internet datagrams have global scope. The fact an Internet datagrams are forwarded based solely on the destination addresses stated in datagram headers and the next hops stored in the forwarding information bases (FIB) of relaying routers allows Internet datagrams to traverse loops, which wastes resources and leaves the Internet open to further attacks. We introduce PEAR (Provenance Enforcement through Addressing and Routing), a new approach for addressing and forwarding of Internet datagrams that enables anonymous forwarding of Internet datagrams, eliminates many of the existing DDoS attacks on the IP Internet, and prevents Internet datagrams from looping, even in the presence of routing-table loops.Comment: Proceedings of IEEE Globecom 2016, 4-8 December 2016, Washington, D.C., US