Win32.Ransom.BlueSky MVID-2022-0632 Code Execution

`Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022  
Original source: https://malvuln.com/advisory/961fa85207cdc4ef86a076bbff07a409.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Win32.Ransom.BlueSky  
Vulnerability: Arbitrary Code Execution  
Description: The BlueSky ransomware looks for and executes arbitrary DLLs in its current working directory. Therefore, we can hijack a vuln DLL, execute our own code, control and terminate the malware pre-encryption. The exploit dll checks if the current directory is "C:\Windows\System32", if not we grab our own process ID and terminate. All basic tests were conducted successfully in a virtual machine environment.  
Family: BlueSky  
Type: PE32  
MD5: 961fa85207cdc4ef86a076bbff07a409  
Vuln ID: MVID-2022-0632  
Disclosure: 08/13/2022  
PoC Video URL: https://www.youtube.com/watch?v=osuS8GjdERM  
  
Exploit/PoC:  
1) Compile the following C code as "CRYPTSP.dll" 32-bit  
2) Place the DLL in same directory as the vuln BlueSky ransomware  
3) Run malware  
  
#include "windows.h"  
  
//By malvuln - August 2022  
//Purpose: PWN BlueSky ransomware MD5: 961fa85207cdc4ef86a076bbff07a409  
//gcc -c CRYPTSP.c -m32  
//gcc -shared -o CRYPTSP.dll CRYPTSP.o -m32  
/** DISCLAIMER:  
Author is NOT responsible for any damages whatsoever by using this software or improper malware  
handling. By using this code you assume and accept all risk implied or otherwise.  
**/  
BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved){  
switch (reason) {  
case DLL_PROCESS_ATTACH:  
MessageBox(NULL, "BlueSky Ransom\nPWNED!!! by Malvuln", "Code Exec PoC", MB_OK);  
TCHAR buf[MAX_PATH];  
if(GetCurrentDirectory(MAX_PATH, buf))  
if(strcmp("C:\\Windows\\System32", buf) != 0){  
HANDLE handle = OpenProcess(PROCESS_TERMINATE, FALSE, getpid());  
if (NULL != handle) {   
TerminateProcess(handle, 0);  
CloseHandle(handle);  
}  
}  
break;  
}  
return TRUE;  
}  
  
  
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`