Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/17da6737cb94c11fa2363772d8eac0b1.txt
Contact: malvuln13@gmail.com
Media: twitter.co Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/17da6737cb94c11fa2363772d8eac0b1.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Trojan-Downloader.Win32.FraudLoad.xevn
Vulnerability: Insecure Permissions
Description: FraudLoad.xevn creates an insecure dir named "usxxxxxxxx.exe" under c: drive and grants change (C) permissions to the authenticated user group. Standard users can rename the executables dropped by the malware to disable it or replace it with their own executable. Then wait for a privileged user to logon to the infected machine to potentially escalate privileges.
Type: PE32
MD5: 17da6737cb94c11fa2363772d8eac0b1
Vuln ID: MVID-2021-0161
Dropped files: config.bin, usxxxxxxxx.exe
Disclosure: 04/05/2021


Exploit/PoC:
C:>cacls usxxxxxxxx.exe
C:usxxxxxxxx.exe BUILTINAdministrators:(OI)(CI)(ID)F
NT AUTHORITYSYSTEM:(OI)(CI)(ID)F
BUILTINUsers:(OI)(CI)(ID)R
NT AUTHORITYAuthenticated Users:(ID)C
NT AUTHORITYAuthenticated Users:(OI)(CI)(IO)(ID)C


C:>cd usxxxxxxxx.exe

C:usxxxxxxxx.exe>dir
Volume in drive C has no label.

Directory of C:usxxxxxxxx.exe

02/10/2018 01:21 AM 146,014 config.bin
02/10/2018 01:21 AM 296,960 usxxxxxxxx.exe
2 File(s) 442,974 bytes


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