Payload.exe is a malicious software, or malware, that exploits and potentially damages your computer system. It is created from payload.c to generate a 64-bit executable file, which is then processed by exe2h to extract the shellcode from the .text segment of the PE file, saving it as a C array to payload_exe_x64.h. When donut is rebuilt, this new shellcode is used for all payloads that it generates. This malware can infect systems through various means such as suspicious downloads, emails, or websites, often without the user's knowledge.
The function of payload.exe extends to performing process hollowing to implant the AsyncRAT client into the target process notepad.exe. This is achieved via a builder that compiles the C# loader stub, adding necessary files and dependencies such as encrypted Quasart RAT (payload.exe) and SharpUnhooker (Apiunhooker.dll) to its resources. This 64-bit console program is designed to disrupt operations, steal personal information, or hold data hostage for ransom.
Finally, payload.exe is further modified by Crypt, which patches some string and opcode within the binary. The malware is then encrypted using the AES algorithm with CBC cipher mode and saved again as “payload.exe.” One key characteristic of this malware is its ability to leverage the "syscall" instruction each time it needs to call the undocumented APIs, making it particularly potent and hard to detect.
Description last updated: 2024-01-06T06:08:57.601Z