Setting up the Firefox extension

The extension replaces the risky click on a suspicious link with a safe one: the page opens in a throwaway, instrumented browser in our cloud, streamed to your tab, while Guard.ch tallies every request, cookie and fingerprint attempt it makes.

Nothing changes about how you browse: the extension does nothing until you invoke it, and then it only hands the link to an investigation. This guide covers what it adds, what a launch does, the team rollout, what it can and cannot do, and troubleshooting.

What it adds to Firefox

• Open in Guard.ch, in the right-click menu of every link. It also works on selected text, so a phishing URL pasted as plain text can go straight into an investigation without touching your clipboard. When a link and a selection are both in play, the link wins.
• A toolbar button, with a paste box for URLs. Its small menu holds the extension's only two extras: a Workspace SSO field for teams (more on that below) and a Settings shortcut into your Guard.ch dashboard.
• A keyboard shortcut. Ctrl+Shift+G (Cmd+Shift+G on a Mac) sends the page in the current tab into an investigation. Firefox lets you rebind it under Manage Extension Shortcuts in the add-ons manager (about:addons).

Install it

The add-on is a free install from Firefox Add-ons and wants Firefox 128 or newer:

1. Open the Guard.ch add-on on Firefox Add-ons.
2. Click Add to Firefox and confirm with Add.
3. In the same confirmation you can tick Run in Private Windows right away; you can change it later in the add-ons manager at any time.
4. Right-click any link and choose Open in Guard.ch. That is the whole workflow; there is no account step and no settings screen.

Prefer to inspect what you install? Download the packed build and load it temporarily: open about:debugging, pick This Firefox, then Load Temporary Add-on and select the file. Temporary add-ons vanish when Firefox closes; outside the store, regular Firefox only keeps signed add-ons permanently.

What happens when you launch

However you trigger it, the extension does exactly one thing: it opens a new tab on guard.ch and hands over the target address in encoded form. The suspicious page itself never loads in your Firefox. What loads is Guard.ch's launcher, which starts a disposable browser in our cloud, streams it into the tab, and switches to the live report. The extension makes no network requests of its own and holds no account; the tab simply runs in your normal signed-in Guard.ch session.

That session is the only requirement. Signed out, the tab lands on the Guard.ch sign-in first; on managed company installs it goes straight to your company's own sign-in instead (see the team section below). And investigations are part of the paid product, so the account needs an active plan or trial; the tab says so plainly if it does not.

What counts as a link

The extension is deliberately strict about what it will launch, so a slip of the mouse cannot start an investigation of nonsense. It accepts:

• Full addresses with http:// or https://.
• Bare domains such as example-shop.com; https:// is assumed in front.
• IP addresses and localhost, with or without a port.
• Selected text that spells one of the above; surrounding spaces are ignored.

Deploying to a team

The extension is built to be pushed. IT can force-install it through Firefox's usual management channel and hand it the workspace's sign-in name in the same policy. From then on, every launch on a managed device routes through the company's Microsoft sign-in: a colleague with a live Microsoft session never sees a form at all, and even opening the Guard.ch sign-in page directly signs them in silently. New members can get their Guard.ch account created on their first sign-in.

The exact rollout steps for every browser and management tool live in your workspace settings under Configure extensions, and the single sign-on behind it has its own step-by-step guide. No IT involved? The same routing can be set by hand: open the toolbar popup's menu, choose Workspace SSO and enter your workspace's sign-in name. A policy-pushed value always wins over the hand-set one; the popup then shows it read-only.

Private windows

Firefox asks at install time whether the add-on may run in private windows. If you skipped the tick, open about:addons, select Guard.ch Companion and set Run in Private Windows to Allow; until then the right-click item stays out of private windows. Installs are per profile, too: each Firefox profile carries its own copy with its own settings.

What it can and cannot do

The extension holds no keys to your browsing. It has no permission to read the pages you visit; it acts only when you invoke it, on the link or page you invoked it for. Its permission list is short and boring: the right-click menu, notifications for its two error messages, momentary access to the current tab at the instant you fire the shortcut, and local storage for its single setting, the optional workspace sign-in name.

The investigation itself runs entirely in our cloud. The suspicious page never loads in your Firefox, nothing downloads to your machine, and the extension phones nobody: no analytics, no requests of its own. The only thing it ever does to the network is open a guard.ch tab.

Works with

Firefox 128 or newer

Install

Firefox Add-ons, free

Permissions

Right-click menu, notifications, the current tab only when invoked, one stored setting

Languages

English and German, following the browser language

Network calls

None of its own. It only ever opens guard.ch tabs.

Runs

In a disposable browser in our cloud, never on your machine

Troubleshooting

Almost everything the extension can run into has a one-line answer:

“That isn't a URL Guard can open.” The launch was rejected before any tab opened: what you right-clicked or pasted does not parse as an address. Full URLs, bare domains, IPs and localhost pass; anything else does not. A stray word in the selection is the usual culprit.

“There's no page to investigate in this tab.” The keyboard shortcut needs an actual page in the active tab. On a blank new tab or a browser-internal page there is nothing to hand over; use the toolbar popup instead.

The right-click item is missing. Three usual causes: a private window without Run in Private Windows set to Allow (see above), a different Firefox profile (each profile installs its own add-ons), or a managed browser whose policy blocks add-on installs; in that case your IT rolls the add-on out centrally.

The shortcut does nothing. Another add-on may have claimed Ctrl+Shift+G, or the binding was cleared. Open about:addons, click the gear and choose Manage Extension Shortcuts to see and rebind it.

The tab lands on a sign-in screen. Expected when you are signed out: sign in once and relaunch. On a managed company install it should not happen; it usually means the pushed workspace name does not match the workspace's sign-in link. The rollout wizard in the dashboard shows the exact value to push.

The tab shows an upgrade screen. The account is signed in but carries no active plan or trial. Extension launches are part of the paid product; start the trial, or ask your workspace manager for a seat.

Firefox refuses the install. The add-on asks for Firefox 128 or newer, and older releases decline it politely. Update Firefox and try again.

Other entry points

However a link reaches Guard.ch, it lands in the same capture and the same report. Browse the other ways in on the integrations page, or see what an investigation actually captures on the product page.