Radamant ransomware tries to load a DLL named "PROPSYS.dll" and execute a hidden PE file "DirectX.exe" from the AppData\Roaming directory. Therefore, we can drop our own DLL to intercept 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. We do not need to rely on hash signatures or third-party products as the malware's flaw does 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 the DLL that 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.
c051794bad7a43ea258023a806d4f4fb80b0f47db0954c5c9d9a7a978d7bf71eDiscovery / credits: Malvuln - (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/6152709e741c4d5a5d793d35817b4c3d.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Trojan-Ransom.Radamant
Vulnerability: Code Execution
Description: Radamant tries to load a DLL named "PROPSYS.dll" and execute a hidden PE file "DirectX.exe" from the AppData\Roaming directory. Therefore, we can drop our own DLL to intercept 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. We do not need to rely on hash signatures or third-party products, the malwares flaw does 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 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.
Family: Radamant
Type: PE32
MD5: 6152709e741c4d5a5d793d35817b4c3d
Vuln ID: MVID-2022-0589
Disclosure: 05/06/2022
Video PoC URL: https://www.youtube.com/watch?v=EToGLoZjR6Q
Exploit/PoC:
1) Compile the following C code as "PROPSYS.dll" 32bit
2) Place the DLL in same directory as the ransomware
3) Optional - Hide it: attrib +s +h "PROPSYS.dll"
4) Run the malware
#include "windows.h"
//By malvuln
//Purpose: Exploit Radamant
//gcc -c PROPSYS.c -m32
//gcc -shared -o PROPSYS.dll PROPSYS.o -m32
BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved){
switch (reason) {
case DLL_PROCESS_ATTACH:
MessageBox(NULL, "Code Exec", "by malvuln", 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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