Headline
Ransom Lockbit 3.0 MVID-2022-0621 Code Execution
Lockbit version 3.0 ransomware looks for and executes DLLs in its current directory. Therefore, we can hijack a DLL, in this case "RstrtMgr.dll", execute our own code, and terminate the malware pre-encryption. The exploit DLL checks if the current directory is “C:\Windows\System32” and if not we grab our process ID and terminate. All basic tests were conducted successfully in a virtual machine environment.
Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022Original source: https://malvuln.com/advisory/38745539b71cf201bb502437f891d799_B.txtContact: [email protected]: twitter.com/malvulnThreat: Ransom Lockbit 3.0 Vulnerability: Code ExecutionDescription: The ransomware apparently now requires a password to execute as noted by "@vxunderground" E.g. "-pass db66023ab2abcb9957fb01ed50cdfa6a". Lockbit looks for and executes DLLs in its current directory. Therefore, we can hijack a vuln DLL in this case "RstrtMgr.dll", execute our own code and terminate the malware pre-encryption. The exploit dll checks 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: LockbitType: PE32MD5: 38745539b71cf201bb502437f891d799Vuln ID: MVID-2022-0621Disclosure: 07/04/2022Video PoC URL: https://www.youtube.com/watch?v=tAXrRcsnzjYExploit/PoC:1) Compile the following C code as "RstrtMgr.dll"2) Place the DLL in same directory as Lockbit 3.03) Optional - Hide it: attrib +s +h "RstrtMgr.dll"4) Run Lockbit 3.0 {04830965-76E6-6A9A-8EE1-6AF7499C1D08}.exe -k LocalServiceNetworkRestricted -pass db66023ab2abcb9957fb01ed50cdfa6a#include "windows.h"//By malvuln - 7/4/2022//Purpose: RCE in Lockbit 3.0 ransomware//MD5: 38745539b71cf201bb502437f891d799//gcc -c RstrtMgr.c -m32//gcc -shared -o RstrtMgr.dll RstrtMgr.o -m32/** 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.**/BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved){ switch (reason) { case DLL_PROCESS_ATTACH: MessageBox(NULL, "Ransom Lockbit 3.0 aka LockShit\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;}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).