Original source: https://malvuln.com/advisory/de613b96174056ef22b42e112d0e61a5.txt
Contact:
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Threat: Trojan-Spy.Win32.KeyLogger.qt
Vulnerability: Insecure Permissions
Description: KeyLogger.qt creates a hidden insecure dir named
"config" under c:\ drive and grants change (C) permissions to the
authenticated user group. Standard users can rename "rundll32.exe"
dropped by the keylogger to disable it or replace with their own
executable. Then wait for a privileged user to logon to the
infected machine to potentially escalate privileges.
Type: PE32
MD5: de613b96174056ef22b42e112d0e61a5
Vuln ID: MVID-2021-0124
Dropped files: rundll32.exe
Disclosure: 03/10/2021
Exploit/PoC:
#include "windows.h"
void main(void){
system("attrib -s -h C:\\config\\rundll32.exe");
system("rename C:\\config\\rundll32.exe 13");
Sleep(1000);
puts("[+] Disabled by renaming C:\\config\\rundll32.exe to 13
...\n");
Sleep(1000);
puts("[+] Trojan-Spy.Win32.KeyLogger.qt PWNED!");
puts("[+] MD5: de613b96174056ef22b42e112d0e61a5");
puts("[+] By Malvuln");
system("pause");
}
C:\config>cacls \config
C:\config BUILTIN\Administrators:(OI)(CI)(ID)F
NT AUTHORITY\SYSTEM:(OI)(CI)(ID)F
BUILTIN\Users:(OI)(CI)(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C
C:\config>dir
Volume in drive C has no label.
Directory of C:\config
File Not Found
C:\config>dir /a
Volume in drive C has no label.
Directory of C:\config
06/16/2012 12:54 AM 585,778 rundll32.exe
1 File(s) 585,778 bytes
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