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Trojan-Ransom.LockerGoga Code Execution
LockerGoga ransomware looks for and loads a DLL named “wow64log.dll” in Windows\System32. Therefore, we can drop our own DLL to intercept and terminate the malware pre-encryption. Four processes are created. For instance, there is “imtvknqq9737.exe” running under AppData\Local\Temp, the process name is “imtvknqq” plus an appended random number. Our exploit DLL will simply display a Win32API message box and call exit(). The exploit DLL must export “InterlockedExchange” function or it fails with an error. We do not need to rely on hash signature or third-party products as the malware’s own flaw will do the work for us. Endpoint protection systems and or antivirus can potentially be killed prior to executing malware, but this method cannot as there’s nothing to kill as the DLL just lives on disk waiting. From a defensive perspective, you can add the DLLs to a specific network share containing important data as a layered approach. 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/3b200c8173a92c94441cb062d38012f6.txtContact: [email protected]: twitter.com/malvulnThreat: Trojan-Ransom.LockerGogaVulnerability: Code ExecutionDescription: LockerGoga looks for and loads a DLL named "wow64log.dll" inWindows\System32. Therefore, we can drop our own DLL to intercept andterminate the malware pre-encryption. Four processes are created E.g."imtvknqq9737.exe" running under AppData\Local\Temp, the process name is"imtvknqq" plus a appended random number. Our exploit dll will simplydisplay a Win32API message box and call exit(). The exploit DLL must export"InterlockedExchange" function or it fails with error. We do not need torely on hash signature or third-party product, the malwares own flaw willdo the work for us. Endpoint protection systems and or antivirus canpotentially be killed prior to executing malware, but this method cannot astheres nothing to kill the DLL just lives on disk waiting. From defensiveperspective you can add the DLLs to a specific network share containingimportant data as a layered approach. All basic tests were conductedsuccessfully in a virtual machine environment.Family: LockerGogaType: PE32MD5: 3b200c8173a92c94441cb062d38012f6Vuln ID: MVID-2022-0587Disclosure: 05/05/2022Video PoC URL: https://www.youtube.com/watch?v=1_7vmbHmCQQExploit/PoC:1) Compile the following C code as "wow64log.dll" as x642) Place the DLL in Windows/System323) Run the malware then BOOM!#include "windows.h"//By malvuln - 5/2022//Target: Trojan-Ransom.LockerGoga//MD5: 3b200c8173a92c94441cb062d38012f6/** DISCLAIMER:Author is NOT responsible for any damages whatsoever by using this softwareor improper malwarehandling. By using this code you assume and accept all risk implied orotherwise.**///compile as x64//gcc -c wow64log.c//gcc -shared -o wow64log.dll wow64log.o//DLL must live under Windows/System32 dirBOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved){ switch (reason) { case DLL_PROCESS_ATTACH: MessageBox(NULL, "Code Exec", "by malvuln", MB_OK); exit(0); break; } return TRUE;}extern __declspec(dllexport) WINBASEAPI LONG WINAPI InterlockedExchange(LONG volatile *Target, LONG Value){ exit(1);}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 duecredit is given. Permission is explicitly given for insertion invulnerability databases and similar, provided that due credit is given tothe author. The author is not responsible for any misuse of the informationcontained herein and accepts no responsibility for any damage caused by theuse or misuse of this information. The author prohibits any malicious useof security related information or exploits by the author or elsewhere. Donot attempt to download Malware samples. The author of this website takesno responsibility for any kind of damages occurring from improper Malwarehandling or the downloading of ANY Malware mentioned on this website orelsewhere. All content Copyright (c) Malvuln.com (TM).