Biblio

With the rapid development of information science and technology, the role of the Internet in daily life is becoming more and more important, but while bringing speed and convenience to the experience, network security issues are endless, and fighting cybercrime will be an eternal topic. In recent years, new types of cyberattacks have made defense and analysis difficult. For example, the memory of network attacks makes some key array evidence only temporarily exist in physical memory, which puts forward higher requirements for attack detection. The traditional memory forensic analysis method for persistent data is no longer suitable for a new type of network attack analysis. The continuous development of memory forensics gives people hope. This paper proposes a network attack detection model based on memory forensic analysis to detect whether the system is under attack. Through experimental analysis, this model can effectively detect network attacks with low overhead and easy deployment, providing a new idea for network attack detection.

Bring Your Own Device (BYOD) is a new trend where employees use their personal devices to connect to their organization networks to access sensitive information and work-related systems. One of the primary challenges in BYOD is to securely delete company data when an employee leaves an organization. In common BYOD programs, the personal device in use is completely wiped out. This may lead to the deletion of personal data during exit procedures. Due to performance and deletion latency, erasure of data in most file systems today results in unlinking the file location and marking data blocks as unused. This may suffice the need of a normal user trying to delete unwanted files but the file content is not erased from the data blocks and can be retrieved with the help of various data recovery and forensic tools. In this paper, we discuss: (1) existing work related to secure deletion, and (2) secure and selective deletion methods that delete only the required files or directories without tampering personal data. We present two per-file deletion methods: Overwriting data and Encryption based deletion which erase specific files securely. Our proposed per-file deletion methods reduce latency and performance overheads caused by overwriting an entire disk.

The era of information technology has, unfortunately, contributed to the tremendous rise in the number of criminal activities. However, digital artifacts can be utilized in convicting cybercriminal and exposing their activities. The digital forensics science concerns about all aspects related to cybercrimes. It seeks digital evidence by following standard methodologies to be admitted in court rooms. This paper concerns about memory forensics for the unique artifacts it holds. Memory contains information about the current state of systems and applications. Moreover, an application's data explains how a criminal has been interacting the application just before the memory is acquired. Memory forensics at the application level is currently random and cumbersome. Targeting specific applications is what forensic researchers and practitioner are currently striving to provide. This paper suggests a general solution to investigate any application. Our solution aims to utilize an application's data structures and variables' information in the investigation process. This is because an application's data has to be stored and retrieved in the means of variables. Data structures and variables' information can be generated by compilers for debugging purposes. We show that an application's information is a valuable resource to the investigator.

Code reuse attacks based on return oriented programming (ROP) are becoming more and more prevalent every year. They started as a way to circumvent operating systems protections against injected code, but they are now also used as a technique to keep the malicious code hidden from detection and analysis systems. This means that while in the past ROP chains were short and simple (and therefore did not require any dedicated tool for their analysis), we recently started to observe very complex algorithms – such as a complete rootkit – implemented entirely as a sequence of ROP gadgets. In this paper, we present a set of techniques to analyze complex code reuse attacks. First, we identify and discuss the main challenges that complicate the reverse engineer of code implemented using ROP. Second, we propose an emulation-based framework to dissect, reconstruct, and simplify ROP chains. Finally, we test our tool on the most complex example available to date: a ROP rootkit containing four separate chains, two of them dynamically generated at runtime.

Modern OS kernels including Windows, Linux, and Mac OS all have adopted kernel Address Space Layout Randomization (ASLR), which shifts the base address of kernel code and data into different locations in different runs. Consequently, when performing introspection or forensic analysis of kernel memory, we cannot use any pre-determined addresses to interpret the kernel events. Instead, we must derandomize the address space layout and use the new addresses. However, few efforts have been made to derandomize the kernel address space and yet there are many questions left such as which approach is more efficient and robust. Therefore, we present the first systematic study of how to derandomize a kernel when given a memory snapshot of a running kernel instance. Unlike the derandomization approaches used in traditional memory exploits in which only remote access is available, with introspection and forensics applications, we can use all the information available in kernel memory to generate signatures and derandomize the ASLR. In other words, there exists a large volume of solutions for this problem. As such, in this paper we examine a number of typical approaches to generate strong signatures from both kernel code and data based on the insight of how kernel code and data is updated, and compare them from efficiency (in terms of simplicity, speed etc.) and robustness (e.g., whether the approach is hard to be evaded or forged) perspective. In particular, we have designed four approaches including brute-force code scanning, patched code signature generation, unpatched code signature generation, and read-only pointer based approach, according to the intrinsic behavior of kernel code and data with respect to kernel ASLR. We have gained encouraging results for each of these approaches and the corresponding experimental results are reported in this paper.

Nowadays, Memory Forensics is more acceptable in Cyber Forensics Investigation because malware authors and attackers choose RAM or physical memory for storing critical information instead of hard disk. The volatile physical memory contains forensically relevant artifacts such as user credentials, chats, messages, running processes and its details like used dlls, files, command and network connections etc. Memory Forensics involves acquiring the memory dump from the Suspect's machine and analyzing the acquired dump to find out crucial evidence with the help of windows pre-defined kernel data structures. While retrieving different artifacts from these data structures, finding the network connections from Windows 7 system's memory dump is a very challenging task. This is because the data structures that store network connections in earlier versions of Windows are not present in Windows 7. In this paper, a methodology is described for efficiently retrieving details of network related activities from Windows 7 x64 memory dump. This includes remote and local IP addresses and associated port information corresponding to each of the running processes. This can provide crucial information in cyber crime investigation.

Precise fingerprinting of an operating system (OS) is critical to many security and forensics applications in the cloud, such as virtual machine (VM) introspection, penetration testing, guest OS administration, kernel dump analysis, and memory forensics. The existing OS fingerprinting techniques primarily inspect network packets or CPU states, and they all fall short in precision and usability. As the physical memory of a VM always exists in all these applications, in this article, we present OS-SOMMELIER+, a multi-aspect, memory exclusive approach for precise and robust guest OS fingerprinting in the cloud. It works as follows: given a physical memory dump of a guest OS, OS-SOMMELIER+ first uses a code hash based approach from kernel code aspect to determine the guest OS version. If code hash approach fails, OS-SOMMELIER+ then uses a kernel data signature based approach from kernel data aspect to determine the version. We have implemented a prototype system, and tested it with a number of Linux kernels. Our evaluation results show that the code hash approach is faster but can only fingerprint the known kernels, and data signature approach complements the code signature approach and can fingerprint even unknown kernels.