Have you visited eBay recently? The site is a popular destination for buying new and used items. You will probably be surprised to learn that eBay scans your computer ports when you visit the site with one Browser.
You can verify it very easily. Use a browser such as Google Chrome, Firefox, Brave, Microsoft Edge, or Vivaldi. Open a new page and press the F12 key to open the Browser Developer Tools.
Open an eBay page on the Network tab in Developer Tools.
Wait for the page to load and look for 127.0.0.1 in the list of links. These are the scans that eBay runs when you log in to the site.
Can you do click in the link to see additional information. This way you will see the port that eBay is currently scanning. The scan is performed by check.js, a JavaScript that runs on eBay when users log in to the site. It uses WebSockets to run searches on your local system using a specified port, and scans are performed regardless of connection status.
The Bleeping Desktop created a handy table listing the ports:
Program | Ebay Name | Port (The Harbour District) |
---|---|---|
Unknown | REF | 63333 |
VNC | VNC | 5900 |
VNC | VNC | 5901 |
VNC | VNC | 5902 |
VNC | VNC | 5903 |
Remote Desktop Protocol | RDP | 3389 |
Aeroadmin | ARO | 5950 |
Ammyy Admin | AMY | 5931 |
TeamViewer | TV0 | 5939 |
TeamViewer | TV1 | 6039 |
TeamViewer | TV2 | 5944 |
TeamViewer | TV2 | 6040 |
Anyplace control | Services | 5279 |
AnyDesk | ANY | 7070 |
Most of these ports are used by remote connection applications, such as VNC, Teamviewer, or Windows Remote Desktop.
The Nullsweep website, which mentioned first this issue, found that the scan does not run on Linux systems.
It is not currently known why eBay scans its visitors' computers. Of course the reactions on Twitter and other sites social media they are too negative. Users generally criticize eBay for scanning ports and for scanning ports as well as users who are not logged into the site.
What can you do;
Block check.js script with a content blocker.
In some browsers, such as Firefox, turn off Web Sockets. EBay is loading script check.js from the following address (currently): https://src.ebay-us.com/fp/check.js
So a regex like || src.ebay-us.com ^ * / check.js should work fine.
The address may change and may differ if you log in from different company addresses such as eBay.de.
The other choice, to disable WebSockets completely, but you may experience incompatibilities and loading problems on other sites.