HEUR.Trojan.Win32.Bayrob.gen Insecure Permissions

HEUR.Trojan.Win32.Bayrob.gen malware suffers from an insecure permissions vulnerability.


MD5 | a29d243d13748526119f17cb924f380e

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/765698ccfb033c86eea6d293235d7ed0.txt
Contact: [email protected]
Media: twitter.com/malvuln

Threat: HEUR.Trojan.Win32.Bayrob.gen
Vulnerability: Insecure Permissions
Description: The malware creates a insecure dir named "rlpzeasjvgnb" 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: 765698ccfb033c86eea6d293235d7ed0
Vuln ID: MVID-2021-0191
Dropped files: mv4aefb186aghbtwsvxglk3h.exe, btqq2r, gzjegrkpac, qaazfq
Disclosure: 04/29/2021

Exploit/PoC:
C:\>cacls rlpzeasjvgnb
C:\rlpzeasjvgnb 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 rlpzeasjvgnb
Volume in drive C has no label.

Directory of C:\rlpzeasjvgnb

04/25/2021 12:21 AM 4 btqq2r
04/25/2021 12:20 AM 0 gzjegrkpac
04/25/2021 12:20 AM 222,208 mv4aefb186aghbtwsvxglk3h.exe
04/25/2021 12:20 AM 6 qaazfq
4 File(s) 222,218 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).

Related Posts