Lessons from Formally Verified Deployed Software Systems (Extended version)

The technology of formal software verification has made spectacular advances, but how much does it actually benefit the development of practical software? Considerable disagreement remains about the practicality of building systems with mechanically-checked proofs of correctness. Is this prospect confined to a few expensive, life-critical projects, or can the idea be applied to a wide segment of the software industry? To help answer this question, the present survey examines a range of projects, in various application areas, that have produced formally verified systems and deployed them for actual use. It considers the technologies used, the form of verification applied, the results obtained, and the lessons that can be drawn for the software industry at large and its ability to benefit from formal verification techniques and tools. Note: a short version of this paper is also available, covering in detail only a subset of the considered systems. The present version is intended for full reference.Comment: arXiv admin note: text overlap with arXiv:1211.6186 by other author

Robust and secure monitoring and attribution of malicious behaviors

Worldwide computer systems continue to execute malicious software that degrades the systemsâ performance and consumes network capacity by generating high volumes of unwanted traffic. Network-based detectors can effectively identify machines participating in the ongoing attacks by monitoring the traffic to and from the systems. But, network detection alone is not enough; it does not improve the operation of the Internet or the health of other machines connected to the network. We must identify malicious code running on infected systems, participating in global attack networks. This dissertation describes a robust and secure approach that identifies malware present on infected systems based on its undesirable use of network. Our approach, using virtualization, attributes malicious traffic to host-level processes responsible for the traffic. The attribution identifies on-host processes, but malware instances often exhibit parasitic behaviors to subvert the execution of benign processes. We then augment the attribution software with a host-level monitor that detects parasitic behaviors occurring at the user- and kernel-level. User-level parasitic attack detection happens via the system-call interface because it is a non-bypassable interface for user-level processes. Due to the unavailability of one such interface inside the kernel for drivers, we create a new driver monitoring interface inside the kernel to detect parasitic attacks occurring through this interface. Our attribution software relies on a guest kernelâ s data to identify on-host processes. To allow secure attribution, we prevent illegal modifications of critical kernel data from kernel-level malware. Together, our contributions produce a unified research outcome --an improved malicious code identification system for user- and kernel-level malware.Ph.D.Committee Chair: Giffin, Jonathon; Committee Member: Ahamad, Mustaque; Committee Member: Blough, Douglas; Committee Member: Lee, Wenke; Committee Member: Traynor, Patric

Measuring the Semantic Integrity of a Process Self

The focus of the thesis is the definition of a framework to protect a process from attacks against the process self, i.e. attacks that alter the expected behavior of the process, by integrating static analysis and run-time monitoring. The static analysis of the program returns a description of the process self that consists of a context-free grammar, which defines the legal system call traces, and a set of invariants on process variables that hold when a system call is issued. Run-time monitoring assures the semantic integrity of the process by checking that its behavior is coherent with the process self returned by the static analysis. The proposed framework can also cover kernel integrity to protect the process from attacks from the kernel-level. The implementation of the run-time monitoring is based upon introspection, a technique that analyzes the state of a computer to rebuild and check the consistency of kernel or user-level data structures. The ability of observing the run-time values of variables reduces the complexity of the static analysis and increases the amount of information that can be extracted on the run-time behavior of the process. To achieve transparency of the controls for the process while avoiding the introduction of special purpose hardware units that access the memory, the architecture of the run-time monitoring adopts virtualization technology and introduces two virtual machines, the monitored and the introspection virtual machines. This approach increases the overall robustness because a distinct virtual machine, the introspection virtual machine, applies introspection in a transparent way both to verify the kernel integrity and to retrieve the status of the process to check the process self. After presenting the framework and its implementation, the thesis discusses some of its applications to increase the security of a computer network. The first application of the proposed framework is the remote attestation of the semantic integrity of a process. Then, the thesis describes a set of extensions to the framework to protect a process from physical attacks by running an obfuscated version of the process code. Finally, the thesis generalizes the framework to support the efficient sharing of an information infrastructure among users and applications with distinct security and reliability requirements by introducing highly parallel overlays

PA-Boot: A Formally Verified Authentication Protocol for Multiprocessor Secure Boot

Hardware supply-chain attacks are raising significant security threats to the boot process of multiprocessor systems. This paper identifies a new, prevalent hardware supply-chain attack surface that can bypass multiprocessor secure boot due to the absence of processor-authentication mechanisms. To defend against such attacks, we present PA-Boot, the first formally verified processor-authentication protocol for secure boot in multiprocessor systems. PA-Boot is proved functionally correct and is guaranteed to detect multiple adversarial behaviors, e.g., processor replacements, man-in-the-middle attacks, and tampering with certificates. The fine-grained formalization of PA-Boot and its fully mechanized security proofs are carried out in the Isabelle/HOL theorem prover with 306 lemmas/theorems and ~7,100 LoC. Experiments on a proof-of-concept implementation indicate that PA-Boot can effectively identify boot-process attacks with a considerably minor overhead and thereby improve the security of multiprocessor systems.Comment: Manuscript submitted to IEEE Trans. Dependable Secure Compu

Software Attestation with Static and Dynamic Techniques

L'abstract è presente nell'allegato / the abstract is in the attachmen