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.
da575e6182321f1a1552e1e5e6da8af1c3614bcb1ff944dc57bf56d87fd9b925Discovery / credits: Malvuln - (John Page - aka hyp3rlinx) (c) 2022
Original source:
https://malvuln.com/advisory/3b200c8173a92c94441cb062d38012f6.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Trojan-Ransom.LockerGoga
Vulnerability: Code Execution
Description: LockerGoga 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 E.g.
"imtvknqq9737.exe" running under AppData\Local\Temp, the process name is
"imtvknqq" plus a 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 error. We do not need to
rely on hash signature or third-party product, the malwares 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
theres nothing to kill the DLL just lives on disk waiting. From 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.
Family: LockerGoga
Type: PE32
MD5: 3b200c8173a92c94441cb062d38012f6
Vuln ID: MVID-2022-0587
Disclosure: 05/05/2022
Video PoC URL: https://www.youtube.com/watch?v=1_7vmbHmCQQ
Exploit/PoC:
1) Compile the following C code as "wow64log.dll" as x64
2) Place the DLL in Windows/System32
3) 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 software
or improper malware
handling. By using this code you assume and accept all risk implied or
otherwise.
**/
//compile as x64
//gcc -c wow64log.c
//gcc -shared -o wow64log.dll wow64log.o
//DLL must live under Windows/System32 dir
BOOL 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);
}
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