BACKDOOR.WIN32.ASYNCRAT / Arbitrary Code Execution

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2024
Original source:
https://malvuln.com/advisory/2337b9a12ecf50b94fc95e6ac34b3ecc.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.AsyncRat
Vulnerability: Arbitrary Code Execution
Description: The malware looks for and executes a x32-bit "CRYPTSP.dll" PE
file in its current directory. Therefore, we can hijack the DLL and execute
our own code to intercept and terminate the malware. Once loaded the
exploit dll will check if the current directory is "C:\Windows\System32",
if not we grab our process ID and terminate. Leverage RansomLord v3 for DLL
generation, while written as a proof-of-concept to specifically defeat
ransomware, it can also be used to generate DLLs to try an exploit other
types of malwares. All basic tests were conducted successfully in a virtual
machine environment.
Family: AsyncRat
Type: PE32
MD5: 2337b9a12ecf50b94fc95e6ac34b3ecc
SHA256: 3c703ecb3e8c54e352ff39fadbe789bb2313f848bd69551b07bf2ed0a58744b9
Vuln ID: MVID-2024-0683
Disclosure: 05/14/2024

Exploit/PoC:
1) Download RansomLord v3
    https://github.com/malvuln/RansomLord
2) Locate the x32 CRYPTSP.dll entry using the -m flag (DLL Map)
3) Use -g flag (Generate Exploit) to output an x32 DLL CRYPTSP.dll, based
on an existing vulnerable malware in the victims list.
4) (Optional) -e flag to setup Windows event IOC logging in the registry,
this will log the SHA256 hash, full path and filename.


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