Researchers at threat intelligence company Group-IB just wrote an intriguing real-life story about an annoyingly simple but surprisingly effective phishing trick known as BitB, short for browser-in-the-browser.

You’ve probably heard of several types of X-in-the-Y attack before, notably MitM and MitB, short for manipulator-in-the-middle and manipulator-in-the-browser.

In a MitM attack, the attackers who want to trick you position themselves somewhere “in the middle” of the network, between your computer and the server you’re trying to reach.

(They might not literally be in the middle, either geographically or hop-wise, but MitM attackers are somewhere along the route, not right at either end.)

The idea is that instead of having to break into your computer, or into the server at the other end, they lure you into connecting to them instead (or deliberately manipulate your network path, which you can’t easily control once your packets exit from your own router), and then they pretend to be the other end – a malevolent proxy, if you like.

They pass your packets on to the official destination, snooping on them and perhaps fiddling with them on the way, then receive the official replies, which they can snoop on and tweak for a second time, and pass them back to you as though you’d connected end-to-end just as you expected.

If you’re not using end-to-end encryption such as HTTPS in order to protect both the confidentiality (no snooping!) and integrity (no tampering!) of the traffic, you are unlikely to notice, or even to be able to detect, that someone else has been steaming open your digital letters in transit, and then sealing them again up afterwards.