Markus Breitenbach

My girlfriend caught a new (?) version of some malware on her machine; what a nuisance and scanners don’t seem to recognize this thing… Some think it’s Vundo others just complain that it’s packed. It doesn’t quite fit the Vundo description,though. MD5 8e06f428178cbfbf12a8372fa6b16d0d size 50688 bytes. It registers some CLSID 721ee819 – b263 – 42e0 – a594 – b82fd0f24bdf , a browser-helper object and various things for notifications by the LSA service plus AppInit_Dll. It constantly restores these keys and it seems that even stomping out all the threads that this DLL-thing spawned everywhere won’t help. I overlooked something and it just comes back as soon as the next GUI app is started. As soon as I know how to get rid of it, I’ll update this post.

Update 1:

It hooks AppInit, the run key using rundll32 to start itself and the LSA notification (something Hijackthis doesn’t check). I can kill all the threads that this thing generates in each executable with ProcessExplorer and regmon will show that the constant checking of the appinit-key stops. However, as soon as the next GUI application is started it is back. So I deleted all the events and mutex objects that things created (I found some clues in the strings in memory) in each executable, again making sure that I didn’t miss anything, and it took a few seconds this time for it to come back. There’s “something” that will load the DLL with OpenProcess to load the DLL into the process space. Since the strings in the DLL show that it opens and writes to process memory this wouldn’t be surprising; question is how I find the threads that do this. Other odd things include that svchost starts a window-less iexplore.exe presumably to upload some stuff to a server or something. It might have some sloppy rootkit (RootkitRevealer went nuts with file-system discrepancies), because I can’t find the DLL (using “dir”) referenced in the keys, yet the tab-extension finds it and overwriting the non-existant file gets an access denied. Some interesting strings from the decrypted memory image of the DLL:

wscntfy.exe wscntfy_mtx mrt.exe explorer.exe iexplore.exe opera.exe firefox.exe Global\ mrt.exe explorer.exe iexplore.exe opera.exe firefox.exe dll .tmp exe rdl InprocServer32 \Internet Explorer\PhishingFilter Enabled Rundll32.exe ” ThreadingModel Both \Internet Explorer\ieuser.exe -Embedding tmp MS Juan cpm las SHELL32.dll ole32.dll OLEAUT32.dll vector<T> too long unknown ntoskrnl.exe ntkrnlmp.exe ntkrnlpa.exe ntkrpamp.exe Mozilla/4.0 (compatible; MSIE 6.0) WinNT 5.1 LoadLibraryW Kernel32 SeDebugPrivilege http://82.98.235.208/form/index.html exficale.com pancolp.com /frame.html url suid dnsapi.dll DnsQuery_A DnsRecordListFree Global\ wuauserv SYSTEM CURRENT_USER Advapi32.dll ConvertStringSidToSidA IsWow64Process kernel32 shell32.dll SHGetKnownFolderPath wininet.dll InternetOpenUrlA HttpOpenRequestA InternetCloseHandle InternetConnectA InternetOpenA InternetSetOptionA InternetQueryOptionA HttpQueryInfoA HttpSendRequestA InternetReadFile HttpAddRequestHeadersA HTTP/1.1 POST Content-Length ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ InprocServer32 setupapi.dll IsUserAdmin BITS b’kJ SHGetFolderPathW CoCreateInstance CoTaskMemFree CoInitialize CoUninitialize CoCreateGuid __dllonexit _onexit _XcptFilter _initterm _amsg_exit _adjust_fdiv WriteFile FlushFileBuffers LocalFree CreateFileW GetFileSize VirtualAlloc ReadFile VirtualFree GetModuleFileNameW lstrcpyW CreateMutexW GetLastError WaitForMultipleObjects GetExitCodeThread lstrlenW OpenMutexW WaitForSingleObject GetProcAddress GetModuleHandleA OpenProcess VirtualAllocEx WriteProcessMemory CreateRemoteThread VirtualFreeEx CreateToolhelp32Snapshot Process32FirstW lstrcmpiW Process32NextW GetCurrentProcess OpenEventW SetEvent Sleep ResetEvent lstrcatW MoveFileW MoveFileExW SetFilePointer SetEndOfFile ReleaseMutex GetModuleFileNameA DisableThreadLibraryCalls ExitProcess LoadLibraryW InitializeCriticalSection DeleteCriticalSection EnterCriticalSection LeaveCriticalSection GetSystemTimeAsFileTime FreeLibrary LoadLibraryA GetLogicalDriveStringsW GetDriveTypeW DeleteFileW GetTickCount GetCurrentThreadId CreateDirectoryW GetSystemTime SystemTimeToFileTime SetFileTime GetWindowsDirectoryA GetVolumeInformationA CreateProcessW OpenMutexA OpenEventA GetCurrentThread GetCurrentProcessId TerminateProcess TerminateThread CreateEventW WideCharToMultiByte HeapAlloc GetProcessHeap HeapFree SetFileAttributesW InterlockedIncrement InterlockedDecrement GetVersion lstrcmpiA lstrcpynW InterlockedExchange InterlockedCompareExchange RtlUnwind QueryPerformanceCounter UnhandledExceptionFilter SetUnhandledExceptionFilter KERNEL32.dll CallNextHookEx SetWindowsHookExA PostMessageA UnhookWindowsHookEx GetSystemMetrics USER32.dll OpenProcessToken LookupPrivilegeValueA AdjustTokenPrivileges RegCreateKeyExW RegDeleteValueW RegFlushKey RegCloseKey RegDeleteKeyW RegQueryValueExW RegSetValueExW RegOpenKeyExW SetSecurityInfo RegEnumValueW GetTokenInformation IsValidSid ConvertSidToStringSidW OpenSCManagerA OpenServiceA ControlService ChangeServiceConfigA AllocateAndInitializeSid CheckTokenMembership FreeSid InitializeSecurityDescriptor SetSecurityDescriptorDacl ConvertStringSidToSidA SetEntriesInAclA DuplicateTokenEx SetTokenInformation GetLengthSid SetThreadToken RegQueryInfoKeyA RegEnumKeyExA RegOpenKeyExA RegQueryValueExA CloseServiceHandle QueryServiceConfigA QueryServiceStatusEx StartServiceA ADVAPI32.dll LocalAlloc RaiseException _except_handler3 222.dll DllCanUnloadNow DllGetClassObject Software\Microsoft\Windows\CurrentVersion\Run Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects CLSID SYSTEM\CurrentControlSet\Control\Lsa Notification Packages Software\Microsoft\Windows NT\CurrentVersion\Windows AppInit_DLLs LoadAppInit_DLLs Software\Microsoft\Internet Explorer\Main Check_Associations Software\Microsoft\Windows\CurrentVersion\Ext\Settings Software\Microsoft SYSTEM\CurrentControlSet\Control\Session Manager PendingFileRenameOperations PendingFileRenameOperations2 Software\Microsoft\Windows\CurrentVersion\Explorer\ShellExecuteHooks Software\Microsoft\Security Center UpdatesDisableNotify Software\Microsoft\Security Center\Svc EnableNotifications EnableNotifications\Ref Software\Microsoft\Windows NT\CurrentVersion DigitalProductId RegisteredOrganization RegisteredOwner C:\WINDOWS\system32\renobuda C:\WINDOWS\system32\calc.exe C:\WINDOWS\system32\defariha.dll C:\WINDOWS\system32\defariha.dll C:\WINDOWS\system32\dadeyisi.dll C:\WINDOWS\system32\vofehafi.dll {721ee819-b263-42e0-a594-b82fd0f24bdf} Global\vimegolatiturew Global\nifuseguji C:\WINDOWS\system32\mrt.exe own1 hdn_dsk .uroledup.com .uroledup.com .?AVCDownloader@@ .?AVCUrlStorage@@ .?AUIObjectWithSite@@ .?AVCConBHO@@ .?AUIUnknown@@ .?AUIClassFactory@@ .?AVCFactory@@

Update 2: Ok, I got rid of it. Turns out there’s no root-kit; the DLL was simply marked as hidden (I feel stupid…). Killing all the threads off, preventing it from re-loading and then re-installing the Service-Pack seems to have gotten rid of it for good.