Discovery / credits: Malvuln - malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/39e22b8b19f6aed59d2def00c4228d56.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Bifrose.ahvb Vulnerability: Insecure Permissions Description: The backdoor creates an insecure dir named "Temp" under c:\ drive, granting change (C) permissions to the authenticated user group. Type: PE32 MD5: 39e22b8b19f6aed59d2def00c4228d56 Vuln ID: MVID-2021-0090 Dropped files: iwbfh482008c.exe Disclosure: 02/15/2021 Exploit/PoC: C:\>cacls \Temp C:\Temp 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:\>dir \Temp Volume in drive C has no label. Directory of C:\Temp 02/14/2021 10:01 PM . 02/14/2021 10:01 PM .. 02/14/2021 10:01 PM 689,664 iwbfh482008c.exe 1 File(s) 689,664 bytes Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).