7279689
An Architectural Approach to Preventing Code Injection Attacks
Code injection attacks, despite being well researched, continue to be a problem today. Modern architectural solutions such as the execute-disable bit and PaX have been useful in limiting the attacks; however, they enforce program layout restrictions and can oftentimes still be circumvented by a determined attacker. We propose a change to the memory architecture of modern processors that addresses the code injection problem at its very root by virtually splitting memory into code memory and data memory such that a processor will never be able to fetch injected code for execution. This virtual split memory system can be implemented as a software-only patch to an operating system and can be used to supplement existing schemes for improved protection. Furthermore, our system is able to accommodate a number of response modes when a code injection attack occurs. Our experiments with both benchmarks and real-world attacks show the system is effective in preventing a wide range of code injection attacks while incurring reasonable overhead.
15335137
Automated Web Patrol with Strider HoneyMonkeys: Finding Web Sites That Exploit Browser Vulnerabilities
Internet attacks that use malicious web sites to install malware programs by exploiting browser vulnerabilities are a serious emerging threat. In response, we have developed an automated web patrol system to automatically identify and monitor these malicious sites. We describe the design and implementation of the Strider HoneyMonkey Exploit Detection System, which consists of a pipeline of “monkey programs” running possibly vulnerable browsers on virtual machines with different patch levels and patrolling the Web to seek out and classify web sites that exploit browser vulnerabilities. Within the first month of utilizing this system, we identified 752 unique URLs hosted on 288 web sites that could successfully exploit unpatched Windows XP machines. The system automatically constructed topology graphs based on traffic redirection to capture the relationship between the exploit sites. This allowed us to identify several major players who are responsible for a large number of exploit pages. By monitoring these 752 exploit-URLs on a daily basis, we discovered a malicious web site that was performing zero-day exploits of the unpatched javaprxy.dll vulnerability and was operating behind 25 exploit-URLs. It was confirmed as the first “inthe-wild”, zero-day exploit of this vulnerability that was reported to the Microsoft Security Response Center. Additionally, by scanning the most popular one million URLs as classified by a search engine, we found over seven hundred exploit-URLs, many of which serve popular content related to celebrities, song lyrics, wallpapers, video game cheats, and wrestling.
1475648
VIOLIN: Virtual Internetworking on Overlay Infrastructure
We propose a novel application-level virtual network architecture called VIOLIN (Virtual Internetworking on OverLay INfrastructure). VIOLINs are isolated virtual networks created on top of an overlay infrastructure (e.g., PlanetLab). Entities in a VIOLIN include virtual end-hosts, routers, and switches implemented by software and hosted by physical overlay hosts. Novel features of VIOLIN include: (1) a VIOLIN is a “virtual world” with its own IP address space. All its computation and communications are strictly con.ned within the VIOLIN. (2) VIOLIN entities can be created, deleted, or migrated on-demand. (3) Value-added network services not widely deployed in the real Internet can be provided in a VIOLIN. We have designed and implemented a prototype of VIOLIN in PlanetLab.
6781814
"Out-of-the-Box" Monitoring of VM-Based High-Interaction Honeypots
Honeypot has been an invaluable tool for the detection and analysis of network-based attacks by either human intruders or automated malware in the wild. The insights obtained by deploying honeypots, especially high-interaction ones, largely rely on the monitoring capability on the honeypots. In practice, based on the location of sensors, honeypots can be monitored either internally or externally. Being deployed inside the monitored honeypots, internal sensors are able to provide a semantic-rich view on various aspects of system dynamics (e.g., system calls). However, their very internal existence makes them visible, tangible, and even subvertible to attackers after break-ins. From another perspective, existing external honeypot sensors (e.g., network sniffers) could be made invisible to the monitored honeypot. However, they are not able to capture any internal system events such as system calls executed. 
 
It is desirable to have a honeypot monitoring system that is invisible, tamper-resistant and yet is capable of recording and understanding the honeypot's system internal events such as system calls. In this paper, we present a virtualization-based system called VMscope which allows us to view the system internal events of virtual machine (VM)-based honeypots from outside the honeypots. Particularly, by observing and interpreting VM-internal system call events at the virtual machine monitor (VMM) layer, VMscope is able to provide the same deep inspection capability as that of traditional inside-the-honeypot monitoring tools (e.g., Sebek) while still obtaining similar tamper-resistance and invisibility as other external monitoring tools. We have built a proof-of-concept prototype by leveraging and extending one key virtualization technique called binary translation. Our experiments with real-world honeypots show that VMscope is robust against advanced countermeasures that can defeat existing internally-deployed honeypot monitors, and it only incurs moderate run-time overhead.
18153606
Virtual distributed environments in a shared infrastructure
We have developed a middleware system that integrates and extends virtual machine and virtual network technologies to support mutually isolated virtual distributed environments in shared infrastructures like the grid and the PlanetLab overlay infrastructure. Integrating virtual network and on-demand virtual machine creation and customization technologies makes virtual distributed environments a reality. The Violin-based middleware system integrates and enhances such technologies to create virtual distributed environments.
325582
Virtual Playgrounds for Worm Behavior Investigation
To detect and defend against Internet worms, researchers have long hoped to have a safe convenient environment to unleash and run real-world worms for close observation of their infection, damage, and propagation. However, major challenges exist in realizing such “worm playgrounds”, including the playgrounds' fidelity, confinement, scalability, as well as convenience in worm experiments. In this paper, we present a virtualization-based platform to create virtual worm playgrounds, called vGrounds, on top of a physical infrastructure. A vGround is an all-software virtual environment dynamically created for a worm attack. It has realistic end-hosts and network entities, all realized as virtual machines (VMs) and confined in a virtual network (VN). The salient features of vGround include: (1) high fidelity supporting real worm codes exploiting real vulnerable services, (2) strict confinement making the real Internet totally invisible and unreachable from inside a vGround, (3) high resource efficiency achieving sufficiently large scale of worm experiments, and (4) flexible and efficient worm experiment control enabling fast (tens of seconds) and automatic generation, re-installation, and final tear-down of vGrounds. Our experiments with real-world worms (including multi-vector worms and polymorphic worms) have successfully exhibited their probing and propagation patterns, exploitation steps, and malicious payloads, demonstrating the value of vGrounds for worm detection and defense research.
6010049
A Vision-Based Endpoint Trajectory and Vibration Control for Flexible Manipulators
This paper addresses a vision-based endpoint trajectory and vibration control approach for flexible manipulators. In this approach, both the trajectory and vibration control are implemented by using an endpoint camera. In order to estimate link vibrations from the visual information, Kalman filter is used. To make the endpoint to follow a specified trajectory, image interpolation approach is introduced. The experimental results prove the effectiveness of the proposed control strategy.
11399358
Constructing and training feed-forward neural networks for pattern classification
A new approach of constructing and training neural networks for pattern classification is proposed. Data clusters are generated and trained sequentially based on distinct local subsets of the training data. Obtained clusters are then used to construct a feed-forward network, which is further trained using standard algorithms operating on the global training set. The network obtained using this approach effectively inherits the knowledge from the local training procedure before improving on its generalization ability through the subsequent global training. Various experiments demonstrate the superiority of this approach over competing methods.
7558919
Siren: Context-aware Computing for Firefighting
Based on an extensive field study of current firefighting practices, we have developed a system called Siren to support tacit communication between firefighters with multiple levels of redundancy in both communication and user alerts. Siren provides a foundation for gathering, integrating, and distributing contextual data, such as location and temperature. It also simplifies the development of firefighting applications using a peer-to-peer network of embedded devices through a uniform programming interface based on the information space abstraction. As a proof of concept, we have developed a prototype context-aware messaging application in the firefighting domain. We have evaluated this application with firefighters and they have found it to be useful for improving many aspects of their current work practices.
30106346
A Genetic Algorithm for Dynamic Routing and Wavelength Assignment in WDM Networks
In this paper, we study the challenging problem of Dynamic Routing and Wavelength Assignment (DRWA) in WDM (Wavelength-Division-Multiplexing) networks with wavelength continuity constraint, and propose an improved genetic algorithm (GA) for it. By adopting a new fitness function to consider simultaneously the path length and number of free wavelengths in cost estimation of a route, the new genetic RWA algorithm can achieve a good load balance among route candidates and result in a lower blocking probability than both the fixed alternative routing algorithm and the previous GA-based algorithm for DRWA, as verified by an extensive simulation study upon the ns-2 network simulator and some typical network topologies.
14786472
CoarseZ Buffer Bandwidth Model in 3D Rendering Pipeline
Depth traffic occupies a major portion of 3D graphics memory bandwidth. In order to reduce depth reading, we propose employing a low-resolution depth buffer, namely CoarseZ buffer, for tile-level depth culling before per-pixel test. The maximum depth of a tile is stored in the corresponding entry of CoarseZ buffer. Simulation results show that a small CoarseZ buffer can achieve remarkably high culling rate and significantly reduce z-reading bandwidth. We build a model that quantifies the influence of the CoarseZ design parameters on its efficiency and bandwidth. Test results of industrial benchmarks show that CoarseZ with tile size of 4 and bit depth of 16 can be a best selection to reduce memory bandwidth