Why is This Website Port Scanning me

published 20.05.2020 01:43

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However, many users run software on their computer that listens on ports for various reasons - online gaming, media sharing, and remote connections are just a few things that consumers might install on a home PC.

So, I wanted to be able to alert on any port scanning on machines as a potential compromise, and a site scanning localhost might trip those alerts.

For instance, Steam (a gaming store and platform) is known to run on port 27036, so a scanner seeing that port open could have reasonable confidence that the user also had steam open while visiting the web site.

Recently, I was tipped off about certain sites performing localhost port scans against visitors, presumably as part of a user fingerprinting and tracking or bot detection.