Browsers & Accounts · How Browsers Keep You Safe · Lesson 5 of 5

Challenge: The Frozen Tab and the Pushy Site

Help a neighbor with a stuck laptop and a flood of pop-up messages.

Mr. Okafor's slow laptop

Your neighbor, Mr. Okafor, calls you over. His laptop fan is loud, and everything moves in slow motion. He has about fifteen tabs open in Chrome, on Windows.

There is more. Every few minutes a message slides up from the corner of the screen. It says his computer has a virus and he must click to clean it. The messages come from a site called streamzone.example, which he visited once to watch a game.

He wants to throw the whole laptop out the window. You ask him to wait, and you sit down.

First, the slowness. You want to find which tab is the problem, without closing all fifteen. He has a half-written letter to his sister in one of them.

Why the other tabs survive

You press Shift+Esc, and Chrome's task manager opens. You click the CPU heading to sort the list.

The top item is a tab from streamzone.example, using far more CPU than anything else. It is a page he forgot was even open. You select it and click End process.

The fan calms down within a few seconds. That one tab now shows a crash page. The tab with his letter is still there, untouched, with every word in place.

Mr. Okafor is surprised. He thought one bad page would take down the whole browser. You explain that each site gets its own walled-off space.

The fake virus messages

Now the messages. You look closely. They aren't from Windows or from his antivirus. Each one shows Chrome's name and the address streamzone.example.

That means they are browser notifications. At some point the site asked to show notifications, and he clicked Allow. He remembers a box that said click Allow to play the video. The game never played, but the messages started that night.

He asks if he should click one, since it says it will clean the virus.

Leaving him safer

You click the icon left of the address on any page, then open Site settings. You go to Notifications and remove streamzone.example from the allowed list. You check the list for any other sites he doesn't recognize, and find none. The corner messages stop.

Before you go, you open the About Google Chrome page. It shows a Relaunch button, because an update is waiting. He saves his letter first, and then you click it. His tabs come back.