Trojan.Ransom.Ryuk.A MVID-2022-0640 Code Execution

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022Original source: https://malvuln.com/advisory/5ac0f050f93f86e69026faea1fbb4450.txtContact: [email protected]: twitter.com/malvulnThreat: Trojan.Ransom.Ryuk.AVulnerability: Arbitrary Code ExecutionDescription: The ransomware looks for and executes DLLs in its current directory. Therefore, we can potentially hijack a vuln DLL execute our own code, control and terminate the malware pre-encryption. Once loaded the exploit dll will check if the current directory is "C:\Windows\System32", if not we grab our process ID and terminate. All basic tests were conducted successfully in a virtual machine environment.Family: RyukType: PE32MD5: 5ac0f050f93f86e69026faea1fbb4450Vuln ID: MVID-2022-0640Disclosure: 09/19/2022Exploit/PoC:1) Compile the following C code as "urlmon.dll"2) Place the DLL in same directory as the ransomware3) Optional - Hide it: attrib +s +h "urlmon.dll"4) Run the malware#include "windows.h"//By malvuln//Purpose: Exploit Ryuk/** DISCLAIMER:Author is NOT responsible for any damages whatsoever by using this software or improper malwarehandling. By using this code you assume and accept all risk implied or otherwise.**///gcc -c urlmon.c -m32//gcc -shared -o urlmon.dll urlmon.o -m32BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved){  switch (reason) {  case DLL_PROCESS_ATTACH:   MessageBox(NULL, "Ryuk\nPWNED By MALVULN", "Code Exec PoC", MB_OK);   TCHAR buf[MAX_PATH];   GetCurrentDirectory(MAX_PATH, TEXT(buf));   int rc = strcmp("C:\\Windows\\System32", TEXT(buf));     if(rc != 0){     HANDLE handle = OpenProcess(PROCESS_TERMINATE, FALSE, getpid());     if (NULL != handle) {           TerminateProcess(handle, 0);       CloseHandle(handle);     }   }    break;  }  return TRUE;}Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).