Backdoor.Win32.Guptachar.20 / Insecure Credential Storage

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source:
https://malvuln.com/advisory/857999d2306f257b80d1b8f6a51ae8b0.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Guptachar.20
Vulnerability: Insecure Credential Storage
Description: The malware runs a web server on TCP port 2015 (default) and
uses BASIC authentication. The credentials "hacker01:imchampgr8" get stored
in a .NFO information file named "GPTCR.NFO" under Windows dir base64
encoded and hidden among many junk NULL bytes.
Family: Guptachar
Type: PE32
MD5: 857999d2306f257b80d1b8f6a51ae8b0
Vuln ID: MVID-2022-0631
Dropped files: GPTCR2.exe
Disclosure: 08/08/2022

Exploit/PoC:
import base64
base64.b64decode("aGFja2VyMDE6aW1jaGFtcGdyOA==")
b'hacker01:imchampgr8'

Web URLs available on the infected host.

http://192.168.18.125:2015/execute.html
http://192.168.18.125:2015/browse.html
http://192.168.18.125:2015/upload.html
http://192.168.18.125:2015/screenshot.html
http://192.168.18.125:2015/keylog.html
http://192.168.18.125:2015/display.html
http://192.168.18.125:2015/shutdown.html
http://192.168.18.125:2015/servopts.html


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