How to find out the id of a person in vk by ip?

Question

In contact with

I went to this site smmscan.ru , after 10 minutes they wrote to me in VK so that I would definitely try this service.
How did they find out my id in VK?

Answer 1

And who wrote? user? or advertising?
if the site has a widget / plugin from VK, they can collect statistics on visitors

Answer 2

On the question in the cap - no.
By the body, most likely they have a bot that sent you a message, and they learned your id from cookies, do you still have authorization on vk?
1 minute after visiting the site, I got a banner

Answer 3

Old topic, these are not cookies, but api vk
https://habrahabr.ru/post/234067/

Answer 4

Recently, topics were moved with an invisible like button, your user was determined by it. But this is slightly inappropriate.

Answer 5

There's an invisible frame

Answer 6

clickjacking.
A frame with a like widget is slipped under the cursor ( https://vk.com/widget_like.php).
When clicked, the widget sends a message to the parent frame (window.postMessage()), which contains the user's id.
The ID is picked up by a regular campaign and sent to the server.
Along the way, a request is made to the VK-API (users.get) and the same popup is shown.
A cookie is also set in order not to do all this on subsequent visits to the site.
Accordingly, until you make a click, they will not receive your id.
Firefox users will be saved by setting privacy.trackingprotection.enabled to true in about:config, then the widget is not loaded at all.
By the way, "cursor: pointer" on the like button burns the office, because it is impossible to get into the frame with the button and tweak the styles there.