Biblio

Microarchitectural attacks have gained popularity lately for the threat they pose and for their stealthiness. They are stealthy as they only exploit common harmless resources accessible at lowest privilege level, e.g. timed memory and cache accesses. Microarchitectural attacks have proven successful on shared cloud instances across VMs, on smartphones with sandboxing, and on numerous embedded platforms. Further they have shown to have catastrophic consequences such as critical data recovery or memory isolation bypassing. Due to the rise of malicious code, app store operators such as Microsoft, Apple and Google are already vetting apps before releasing them. Microarchitectural attacks however still bypass such detection mechanisms as they mainly utilize standard resources and look harmless. Given the rise of malicious code in app stores and in online repositories it becomes essential to scan applications for such stealthy attacks to prevent their distribution. We present a static code analysis tool, MASCAT, capable of scanning for ever-evolving microarchitectural attacks. MASCAT can be used by app store service providers to perform large scale fully automated analysis of applications. The initial MASCAT suite is built to include cache/DRAM access attacks and rowhammer. MASCAT detects several patterns that are common and necessary to execute microarchitectural attacks. MASCAT currently has a detection rate of 96% and an average false positive rate tested in 1200 applications of 0.75%. Further, our tool can easily be extended to cover newer attack vectors as they emerge

Most of the countries evaluate their energy networks in terms of national security and define as critical infrastructure. Monitoring and controlling of these systems are generally provided by Industrial Control Systems (ICSs) and/or Supervisory Control and Data Acquisition (SCADA) systems. Therefore, this study focuses on the cyber-attack vectors on SCADA systems to research the threats and risks targeting them. For this purpose, TCP/IP based protocols used in SCADA systems have been determined and analyzed at first. Then, the most common cyber-attacks are handled systematically considering hardware-side threats, software-side ones and the threats for communication infrastructures. Finally, some suggestions are given.

Software Defined Network (SDN) architecture is a new and novel way of network management mechanism. In SDN, switches do not process the incoming packets like conventional network computing environment. They match for the incoming packets in the forwarding tables and if there is none it will be sent to the controller for processing which is the operating system of the SDN. A Distributed Denial of Service (DDoS) attack is a biggest threat to cyber security in SDN network. The attack will occur at the network layer or the application layer of the compromised systems that are connected to the network. In this paper a machine learning based intelligent method is proposed which can detect the incoming packets as infected or not. The different machine learning algorithms adopted for accomplishing the task are Naive Bayes, K-Nearest neighbor (KNN) and Support vector machine (SVM) to detect the anomalous behavior of the data traffic. These three algorithms are compared according to their performances and KNN is found to be the suitable one over other two. The performance measure is taken here is the detection rate of infected packets.

The advent of HTML 5 revives the life of cross-site scripting attack (XSS) in the web. Cross Document Messaging, Local Storage, Attribute Abuse, Input Validation, Inline Multimedia and SVG emerge as likely targets for serious threats. Introduction of various new tags and attributes can be potentially manipulated to exploit the data on a dynamic website. The XSS attack manages to retain a spot in all the OWASP Top 10 security risks released over the past decade and placed in the seventh spot in OWASP Top 10 of 2017. It is known that XSS attempts to execute scripts with untrusted data without proper validation between websites. XSS executes scripts in the victim's browser which can hijack user sessions, deface websites, or redirect the user to the malicious site. This paper focuses on the development of a browser extension for the popular Google Chromium browser that keeps track of various attack vectors. These vectors primarily include tags and attributes of HTML 5 that may be used maliciously. The developed plugin alerts users whenever a possibility of XSS attack is discovered when a user accesses a particular website.

OpenFlow has recently emerged as a powerful paradigm to help build dynamic, adaptive and agile networks. By decoupling control plane from data plane, OpenFlow allows network operators to program a centralized intelligence, OpenFlow controller, to manage network-wide traffic flows to meet the changing needs. However, from the security's point of view, a buggy or even malicious controller could compromise the control logic, and then the entire network. Even worse, the recent attack Stuxnet on industrial control systems also indicates the similar, severe threat to OpenFlow controllers from the commercial operating systems they are running on. In this paper, we comprehensively studied the attack vectors against the OpenFlow critical component, controller, and proposed a cross layer diversity approach that enables OpenFlow controllers to detect attacks, corruptions, failures, and then automatically continue correct execution. Case studies demonstrate that our approach can protect OpenFlow controllers from threats coming from compromised operating systems and themselves.

A cyber-attack detection system issues alerts when an attacker attempts to coerce a trusted software application to perform unsafe actions on the attacker's behalf. One way of issuing such alerts is to create an application-agnostic cyber- attack detection system that responds to prevalent software vulnerabilities. The creation of such an autonomic alert system, however, is impeded by the disparity between implementation language, function, quality-of-service (QoS) requirements, and architectural patterns present in applications, all of which contribute to the rapidly changing threat landscape presented by modern heterogeneous software systems. This paper evaluates the feasibility of creating an autonomic cyber-attack detection system and applying it to several exemplar web-based applications using program transformation and machine learning techniques. Specifically, we examine whether it is possible to detect cyber-attacks (1) online, i.e., as they occur using lightweight structures derived from a call graph and (2) offline, i.e., using machine learning techniques trained with features extracted from a trace of application execution. In both cases, we first characterize normal application behavior using supervised training with the test suites created for an application as part of the software development process. We then intentionally perturb our test applications so they are vulnerable to common attack vectors and then evaluate the effectiveness of various feature extraction and learning strategies on the perturbed applications. Our results show that both lightweight on-line models based on control flow of execution path and application specific off-line models can successfully and efficiently detect in-process cyber-attacks against web applications.

McEliece is a public-key cryptosystem based on error correcting codes. It has the ability to resist quantum-computer attacks which can break different modern public key cryptosystems such as RSA. Further more, it's encryption and decryption are very fast and have good characteristics for data parallel processing. Nowadays, modern graphic processing units (GPUs) are available in almost all hardware platforms. GPUs can comprise many compute cores which can process a huge data in parallel. In this paper, different implementations of McEliece cryptosystem are explored on NVIDIA GTX780 GPU using OpenCL framework. Our implementation results show that GPU is 331x faster than CPU when apply local memory with vector data-type to encrypt 216 messages.

When created, the Java platform was among the first runtimes designed with security in mind. Yet, numerous Java versions were shown to contain far-reaching vulnerabilities, permitting denial-of-service attacks or even worse allowing intruders to bypass the runtime's sandbox mechanisms, opening the host system up to many kinds of further attacks. This paper presents a systematic in-depth study of 87 publicly available Java exploits found in the wild. By collecting, minimizing and categorizing those exploits, we identify their commonalities and root causes, with the goal of determining the weak spots in the Java security architecture and possible countermeasures. Our findings reveal that the exploits heavily rely on a set of nine weaknesses, including unauthorized use of restricted classes and confused deputies in combination with caller-sensitive methods. We further show that all attack vectors implemented by the exploits belong to one of three categories: single-step attacks, restricted-class attacks, and information hiding attacks. The analysis allows us to propose ideas for improving the security architecture to spawn further research in this area.

In the Serious Game Operation Digital Chameleon red and blue teams develop attack and defense strategies to explore IT-Security of Critical Infrastructures as part of an IT-Security training. Operation Digital Chameleon is the training game of the IT-Security Matchplay series in the IT-Security for Critical Infrastructure research program funded by BMBF. We present the design of Operation Digital Chameleon in its current form as well as results from game \#3. We analyze the potential and innovation capability of Operation Digital Chameleon as an Open Innovation method for the domain of IT-Security of Critical Infrastructures. We find that Operation Digital Chamaeleon facilitates creativity, opens the process of IT-Security strategy development and –despite being designed for training purposes – opens the process to explore innovative attack vectors.

To improve the information assurance of mission execution over modern IT infrastructure, new cyber defenses need to not only provide security benefits, but also perform within a given cost regime. Current approaches for validating and integrating cyber defenses heavily rely on manual trial-and-error, without a clear and systematic understanding of security versus cost tradeoffs. Recent work on model-based analysis of cyber defenses has led to quantitative measures of the attack surface of a distributed system hosting mission critical applications. These metrics show great promise, but the cost of manually creating the underlying models is an impediment to their wider adoption. This paper describes an experimentation framework for automating multiple activities associated with model construction and validation, including creating ontological system models from real systems, measuring and recording distributions of resource impact and end-to-end performance overhead values, executing real attacks to validate theoretic attack vectors found through analytic reasoning, and creating and managing multi-variable experiments.

Attacks that leverage USB as an attack vector are gaining popularity. While attention has so far focused on attacks that either exploit the host's USB stack or its unrestricted device privileges, it is not necessary to compromise the host to mount an attack over USB. This paper describes and implements a USB sniffing attack. In this attack a USB device passively eavesdrops on all communications from the host to other devices, without being situated on the physical path between the host and the victim device. To prevent this attack, we present UScramBle, a lightweight encryption solution which can be transparently used, with no setup or intervention from the user. Our prototype implementation of UScramBle for the Linux kernel imposes less than 15% performance overhead in the worst case.

In this paper, we analyze the fundamental vulnerabilities of Spin-Torque-Transfer RAM on magnetic field and temperature that can be exploited by adversaries with an intent to trigger soft performance failures. We present novel attack vectors and their impact on memory performance (i.e., read, write and retention). We propose a novel low-overhead clock frequency-adaptation technique to mitigate the attack. Our analysis indicate slowing the clock frequency by 85% restores 170 mV of sense margin under 300 Oe DC magnetic field. In addition, 66% operating clock slowdown allows STTRAM to tolerate over 300 Oe AC magnetic field.

Cache side-channel attacks have been extensively studied on x86 architectures, but much less so on ARM processors. The technical challenges to conduct side-channel attacks on ARM, presumably, stem from the poorly documented ARM cache implementations, such as cache coherence protocols and cache flush operations, and also the lack of understanding of how different cache implementations will affect side-channel attacks. This paper presents a systematic exploration of vectors for flush-reload attacks on ARM processors. flush-reload attacks are among the most well-known cache side-channel attacks on x86. It has been shown in previous work that they are capable of exfiltrating sensitive information with high fidelity. We demonstrate in this work a novel construction of flush-reload side channels on last-level caches of ARM processors, which, particularly, exploits return-oriented programming techniques to reload instructions. We also demonstrate several attacks on Android OS (e.g., detecting hardware events and tracing software execution paths) to highlight the implications of such attacks for Android devices.

Physical unclonable functions (PUFs) utilize manufacturing ariations of circuit elements to produce unpredictable response to any challenge vector. The attack on PUF aims to predict the PUF response to all challenge vectors while only a small number of challenge-response pairs (CRPs) are known. The target PUFs in this paper include the Arbiter PUF (ArbPUF) and the Memristor Crossbar PUF (MXbarPUF). The manufacturing variations of the circuit elements in the targeted PUF can be characterized by a weight vector. An optimization-theoretic attack on the target PUFs is proposed. The feasible space for a PUF's weight vector is described by a convex polytope confined by the known CRPs. The centroid of the polytope is chosen as the estimate of the actual weight vector, while new CRPs are adaptively added into the original set of known CRPs. The linear behavior of both ArbPUF and MXbarPUF is proven which ensures that the feasible space for their weight vectors is convex. Simulation shows that our approach needs 71.4% fewer known CRPs and 86.5% less time than the state-of-the-art machine learning based approach.

Unlike a random, run-of-the-mill website infection, in a strategic web attack, the adversary carefully chooses the target frequently visited by an organization or a group of individuals to compromise, for the purpose of gaining a step closer to the organization or collecting information from the group. This type of attacks, called "watering hole", have been increasingly utilized by APT actors to get into the internal networks of big companies and government agencies or monitor politically oriented groups. With its importance, little has been done so far to understand how the attack works, not to mention any concrete step to counter this threat. In this paper, we report our first step toward better understanding this emerging threat, through systematically discovering and analyzing new watering hole instances and attack campaigns. This was made possible by a carefully designed methodology, which repeatedly monitors a large number potential watering hole targets to detect unusual changes that could be indicative of strategic compromises. Running this system on the HTTP traffic generated from visits to 61K websites for over 5 years, we are able to discover and confirm 17 watering holes and 6 campaigns never reported before. Given so far there are merely 29 watering holes reported by blogs and technical reports, the findings we made contribute to the research on this attack vector, by adding 59% more attack instances and information about how they work to the public knowledge. Analyzing the new watering holes allows us to gain deeper understanding of these attacks, such as repeated compromises of political websites, their long lifetimes, unique evasion strategy (leveraging other compromised sites to serve attack payloads) and new exploit techniques (no malware delivery, web only information gathering). Also, our study brings to light interesting new observations, including the discovery of a recent JSONP attack on an NGO website that has been widely reported and apparently forced the attack to stop.

Given a stream of heterogeneous graphs containing different types of nodes and edges, how can we spot anomalous ones in real-time while consuming bounded memory? This problem is motivated by and generalizes from its application in security to host-level advanced persistent threat (APT) detection. We propose StreamSpot, a clustering based anomaly detection approach that addresses challenges in two key fronts: (1) heterogeneity, and (2) streaming nature. We introduce a new similarity function for heterogeneous graphs that compares two graphs based on their relative frequency of local substructures, represented as short strings. This function lends itself to a vector representation of a graph, which is (a) fast to compute, and (b) amenable to a sketched version with bounded size that preserves similarity. StreamSpot exhibits desirable properties that a streaming application requires: it is (i) fully-streaming; processing the stream one edge at a time as it arrives, (ii) memory-efficient; requiring constant space for the sketches and the clustering, (iii) fast; taking constant time to update the graph sketches and the cluster summaries that can process over 100,000 edges per second, and (iv) online; scoring and flagging anomalies in real time. Experiments on datasets containing simulated system-call flow graphs from normal browser activity and various attack scenarios (ground truth) show that StreamSpot is high-performance; achieving above 95% detection accuracy with small delay, as well as competitive time and memory usage.  

The term “Advanced Persistent Threat” refers to a well-organized, malicious group of people who launch stealthy attacks against computer systems of specific targets, such as governments, companies or military. The attacks themselves are long-lasting, difficult to expose and often use very advanced hacking techniques. Since they are advanced in nature, prolonged and persistent, the organizations behind them have to possess a high level of knowledge, advanced tools and competent personnel to execute them. The attacks are usually preformed in several phases - reconnaissance, preparation, execution, gaining access, information gathering and connection maintenance. In each of the phases attacks can be detected with different probabilities. There are several ways to increase the level of security of an organization in order to counter these incidents. First and foremost, it is necessary to educate users and system administrators on different attack vectors and provide them with knowledge and protection so that the attacks are unsuccessful. Second, implement strict security policies. That includes access control and restrictions (to information or network), protecting information by encrypting it and installing latest security upgrades. Finally, it is possible to use software IDS tools to detect such anomalies (e.g. Snort, OSSEC, Sguil).

Cross-Site Scripting (XSS) is a common attack technique that lets attackers insert the code in the output application of web page which is referred to the web browser of visitor and then the inserted code executes automatically and steals the sensitive information. In order to prevent the users from XSS attack, many client- side solutions have been implemented; most of them being used are the filters that sanitize the malicious input. However, many of these filters do not provide prevention to the newly designed sophisticated attacks such as multiple points of injection, injection into script etc. This paper proposes and implements an approach based on encoding unfiltered reflections for detecting vulnerable web applications which can be exploited using above mentioned sophisticated attacks. Results prove that the proposed approach provides accurate higher detection rate of exploits. In addition to this, an implementation of blocking the execution of malicious scripts have contributed to XSS-Me: an open source Mozilla Firefox security extension that detects for reflected XSS vulnerabilities which can be considered as an effective solution if it is integrated inside the browser rather than being enforced as an extension.