[miles]

> I have a 2009 MacBook Pro (Core2Duo + 4GB of ram), I've added an SSD years ago, and it runs absolutely fine, I use it almost daily to browse the web. ... the updates stopped at El Capitan unfortunately. ... I'm not that bothered.

You might want to consider running Manjaro[0] or Haiku[1] instead (I've had great luck with both on older MacBooks [2,3]).

Nessus reports El Capitan as a "Critical" vulnerability due to lack of security updates:

According to its self-reported version number, the Unix operating system running on the remote host is no longer supported.

Lack of support implies that no new security patches for the product will be released by the vendor. As a result, it is likely to contain security vulnerabilities.

...

Mac OS X 10.11.6 (intel) support ended.

Upgrade to Mac OS X 10.14 / 10.13 / 10.12.

[0] https://manjaro.org

[1] https://www.haiku-os.org

[2] https://tinyapps.org/blog/201811010700_linux_for_2009_macboo...

[3] https://tinyapps.org/docs/haiku/

[gambiting]

Sure, but it's a laptop to look up some kitchen recipes, watch YouTube and use facetime occasionally. If it has security vulnerabilities I'm genuinely not bothered - any minute spent installing another system is a minute just not worth it for me.

[wila]

Which is fine if you keep that laptop in its own isolated network. Otherwise it might end up being used for gaining access to other machines in your network.

[tomxor]

i've got a 2008 MBP, these are great Linux machines unlike the latest macs. Very well supported hardware. Only issue I had was the custom gmux chip but it only takes a few lines of c to make a switch.