Trojan.Win32.Pincav.cmfl Insecure Permissions

Trojan.Win32.Pincav.cmfl malware suffers from an insecure permissions vulnerability.

MD5 | b237580a2e1707ad533440f0bedecdcc

Discovery / credits: Malvuln - (c) 2021
Original source:
Contact: [email protected]

Threat: Trojan.Win32.Pincav.cmfl
Vulnerability: Insecure Permissions
Description: The trojan creates an insecure dir named "Windupdt" under c:\ drive, granting change (C) permissions to authenticated users group. Standard users can rename the malware and reboot to disable it or replace it with their own executable to escalate privileges when a privileged user logs on. The malware also creates registry key under HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run for persistence. To successfully rename the malware we have to call Windows "attrib -h" command to unhide the executable or the rename will fail.
Type: PE32
MD5: 9d296ebd6b4f79457fcc61e38dcce61e
Vuln ID: MVID-2021-0104
Dropped files: winupdate.exe
Disclosure: 02/21/2021

#include "stdio.h"
#include "windows.h"

void main(void){

system("attrib -h C:\\Windupdt\\winupdate.exe");
puts("Unhiding the malware to rename it...");
system("RENAME C:\\Windupdt\\winupdate.exe 13");

puts("[+] Disabled persistence by renaming winupdate.exe to 13 ...\n");
puts("Restart your computer ...");

puts("[+] Trojan.Win32.Pincav.cmfl PWNED!\n");
puts("[+] MD5: 9d296ebd6b4f79457fcc61e38dcce61e\n");
puts("[+] By Malvuln\n");


C:\>cacls Windupdt
C:\Windupdt BUILTIN\Administrators:(OI)(CI)(ID)F
NT AUTHORITY\Authenticated Users:(ID)C
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C

C:\>dir /a \Windupdt
Volume in drive C has no label.

Directory of C:\Windupdt

06/14/2012 11:46 PM 707,094 winupdate.exe
1 File(s) 707,094 bytes
2 Dir(s) 49,773,490,176 bytes free

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