How do you analyze the network traffic generated by a PE file during dynamic analysis?

Preparing the environment for analyzing network traffic generated by a Portable Executable (PE) file during dynamic analysis involves creating a controlled and isolated environment to observe the behavior of the file without risking the security of the host system. Employ a virtual machine (VM) to create an isolated environment. Tools like VirtualBox, VMware, or Hyper-V. Before running the PE file, take a snapshot of the virtual machine. You can use tools such as tcpdump and Wireshark, some debuggers OllyDbg, IDA Pro, or x64dbg, and Process Monitor, Process Explorer, or Cuckoo Sandbox can provide insights into file system and registry changes, process activity, and network interactions

VM sandbox environment is ideal for dynamic analysis. You can use freely available tools such as Oracle VirtualBox, VMware workstation player for build your virtual machine on to of that. FlareVM and Remnux is free tools which are specifically designed for the malware analysis both static and dynamic. With both the VMs there are ton of handy tools included and use can utilize those tools for the analysis process.

Ao realizar a execução de um arquivo considerado potencialmente malicioso em uma sandbox, você poderá determinar qual momento e o que deseja capturar. Dentre eles, o tráfego de rede poderá ser obtido do artefato visando identificar qual a comunicação a ser realizada com o ator malicioso, levando em consideração a possibilidade de identificar qual o C2 utilizado. Além disso, poderá verificar quais parâmetros e conteúdos estão sendo enviados e recebidos a depender do protocolo de comunicação.

Execute the PE file within the controlled environment. Observe its behavior, such as the creation of processes, file system changes, registry modifications, and network communication. Use dynamic analysis tools to monitor the behavior of the PE file: - Debugger: Attach a debugger to the running process to step through the code, set breakpoints, and analyze the runtime behavior. - Process Monitor: Monitor file system, registry, and process activity to identify any suspicious changes. - Wireshark or TCPDump: Capture and analyze network traffic to understand communication patterns and identify potential malicious connections.

When its come to the capture network traffic you can use iNetSim, fakenet-ng kind of tool for network traffic simulation, and analyze the logs from that tools is more handy to get quick understanding for the traffic. Arkime Also handy tool to use when it's come to the .pcap analysis like Wireshark

Analyzing the network behavior of a PE file is crucial for understanding its communication with external entities, identifying potential threats, and enhancing overall cybersecurity. Several tools can be employed to conduct networking analysis on PE files sucha as: Wireshark, TCPView, Process Monitor, API Monitor, among others. When using these tools, it's crucial to perform analysis in a controlled and isolated environment to prevent potential harm to the host system. Additionally, combining multiple tools for a comprehensive analysis can provide a more accurate understanding of the PE file's networking behavior

Utilizando ferramentas mencionadas já na descrição, podemos adicionar o NetWorkMiner, Wireshark, Fiddler entre outros, dos quais podem ser utilizados para obter informações do tráfego e indicar qualquer tipo de comportamento malicioso.

Decoder and decrypter tools, such as CyberChef, XORSearch, and others, offer several benefits in the realm of cybersecurity and digital forensics. These tools are designed to assist analysts in decoding, decrypting, or transforming data in various formats, providing valuable insights and aiding in the analysis of malicious artifacts. They are instrumental in extracting information from various artifacts, such as network captures, logs, or forensic images. They can decode encoded data, recover hidden strings, and unveil critical details that might be concealed.

Malware analysis of network traffic is an ongoing and dynamic process. It requires a combination of technical skills, tools, and a deep understanding of network protocols and malware behavior. The goal is to uncover the tactics, techniques, and procedures (TTPs) employed by the malware, which can inform effective cybersecurity measures and responses. You should look for tools designed to identify and highlight differences between two network captures. It can be useful for identifying changes in network behavior, detecting anomalies, or comparing different instances of network traffic.

Adapting the report structure to the specific details and characteristics of the analyzed PE file and its network traffic will enhance the clarity and usefulness of the report for both technical and non-technical audiences. You should create a executive summary, introduction, explain the methodology, bring the evidences, such as C&Cs, Patterns, Payloads, drawing in map, explain how the attack happened and bring the recommendations.

Learning about Portable Executable (PE) traffic analysis, especially in the context of malware analysis and cybersecurity, can be enhanced through participation in communities and attending relevant events. These platforms provide opportunities to connect with experts, share knowledge, and stay updated on the latest developments. You can participate in conferences sucha as: DEFCON, BlackHat, Bsides, HITB, etc. Participating in these communities and attending events can provide valuable networking opportunities, access to cutting-edge research, and exposure to practical insights from experienced professionals in the field of PE traffic analysis and malware analysis.

After executing the malware dynamically, we provision a detailed report on how does the malware behave? what are the techniques used for persistence? Is it utilizing any tehniques of obfuscation to bybass AV? what are imported libraries? It it opening a channel for C2C? All the aforementioned could be done using windows sysinternals and others metrics along with a framework like MITREAttack to draw the Tactics, Techniques, and Procedure that lie in the malware.