Backdoor.Win32.DarkKomet.irv malware suffers from an insecure permissions vulnerability.
a4a25186b44b304f17b0275fe121d4c5Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/341b2c3222122bd25c8509fc09534dec.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Backdoor.Win32.DarkKomet.irv
Vulnerability: Insecure Permissions
Description: DarkKomet.irv creates an insecure hidden dir named "updter" under c:\ drive and drops executable "updt.exe". The backdoor grants change (C) permissions to the authenticated user group for the "updter" dir. Standard users can rename the malware 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: 341b2c3222122bd25c8509fc09534dec
Vuln ID: MVID-2021-0118
Dropped files: updt.exe
Disclosure: 03/02/2021
Exploit/PoC:
gcc -c DarkKomet_Exploit.c
gcc -o DarkKomet_Exploit.exe DarkKomet_Exploit.o
"DarkKomet_Exploit.c"
#include "windows.h"
void main(void){
system("attrib -s -h C:\\updter\\updt.exe");
system("rename C:\\updter\\updt.exe 13");
Sleep(1000);
puts("[+] Disabled by renaming C:\\updter\\updt.exe to 13 ...\n");
Sleep(1000);
puts("[+] Backdoor.Win32.DarkKomet.irv PWNED!");
puts("[+] MD5: 341b2c3222122bd25c8509fc09534dec");
puts("[+] By Malvuln");
system("pause");
}
C:\>cacls C:\updter 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:\>cd updter
C:\updter>dir
Volume in drive C has no label.
Directory of C:\updter
File Not Found
C:\updter>dir /a
Volume in drive C has no label.
Directory of C:\updter
06/17/2012 12:59 AM 827,392 updt.exe
1 File(s) 827,392 bytes
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