Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b64761b0c81c5f8d…

MALICIOUS

Office (OOXML)

19.5 KB Created: 2021-09-06 09:09:00 UTC Authoring application: Microsoft Office Word 15.0000 First seen: 2021-09-17
MD5: e6bf7ba7e24a2b7c023875fc47459dae SHA-1: 03bf0a47dd96de7e44ce17f6acb711d0515950c7 SHA-256: b64761b0c81c5f8d70b0c0dba84f1113b6c645d3017779b22291b20191cd6a1b
262 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.003 Windows Command Shell

The sample contains a VBA macro that is triggered by the AutoClose event. This macro writes the content of the first paragraph to a file named 'xxx.txt' in the 'c:\programdata\' directory and then executes the calculator application using 'WScript.Shell'. This indicates an attempt to execute arbitrary code and potentially download further payloads.

Heuristics 7

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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/2012/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)

Related samples 1

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

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) 666 bytes
SHA-256: 418632e1e6eb6320c91040f3af5b1479e26455445535c28f7dec4bbfd6402094
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 = "模块1"
Sub AutoClose()

Dim xxxa As String
xxxa = "c:\programdata\"
Open xxxa & "xxx.txt" For Output As #1
Dim xxxb As Range
Set xxxb = ActiveDocument.Paragraphs(1).Range
Print #1, ActiveDocument.Paragraphs(1).Range
Close #1

Dim WshShell, oExec
Set WshShell = CreateObject("WScript.Shell")
Set oExec = WshShell.Exec("calc")



End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15360 bytes
SHA-256: 5b076cd056d09b0e7f1facde5dc7e69c9a57d796fe3c3c4e8126ce7ab6079917

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