Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 71524c943e49720c…

MALICIOUS

Office (OOXML)

16.6 KB Created: 2021-06-11 02:28:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-17
MD5: 1f18cc1f5063de3ecf5cf2782d52b98a SHA-1: 4b33af7454e1d5913be8c920f5b628baac83976d SHA-256: 71524c943e49720c98b7e979488ad51f7228cc215403f349f85dff6b4aa19473
182 Risk Score

Malware Insights

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

The sample is an OOXML document containing VBA macros, specifically an AutoOpen macro. This macro utilizes `CreateObject` and `CallByName` to construct and execute a PowerShell command. The reconstructed command is `powershell.exe -exec bypass -c 'powershell.exe'`, which is likely intended to download and execute a second-stage payload. The presence of the AutoOpen macro and the execution of PowerShell strongly suggest a malicious intent, likely delivered via spearphishing.

Heuristics 6

  • 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 In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn 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/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2018/wordml/cexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2018/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn 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) 1143 bytes
SHA-256: d31c2395544f434e0c775786ab5ce43ea9c71f94f04d123a73f7d5d89078c285
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"
Sub AutoOpen()
        a = ""
        E = "p"
        f = "owe"
        g = "rsh"
        h = "el"
        i = "l."
        j = "e"
        k = "xe"
        
        i = E + f + g + h + i + j + k
        
        VBA$.Interaction.CallByName! a, [b], c, i, d
        

End Sub

Sub AutoOpen()
        
        cmdType = "Shell.Appl" + "ication"
        cmdCommand = "ShellExe" + "cute"
        cmdParams = ""
        E = "p"
        f = "owe"
        g = "rsh"
        h = "el"
        i = "l."
        j = "e"
        k = "xe"
        
        i = E + f + g + h + i + j + k

        cmdParams = cmdParams + " -exec bypass -c '"
        Set cmdObj = Interaction.CreateObject(cmdType)
        VBA$.Interaction.CallByName! cmdObj, [cmdCommand], VbMethod, i, cmdParams
        

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 10240 bytes
SHA-256: e23d470022f7ba07649f42851a484a5717b7df580329d8b330b6ba82885870d9

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