Where do I start on all links...

This is an error that has been elevated to critical error status because it occurred during the primary error mechanism reporting system itself (possibly due to it occurring within the standard output framework). It may be masking a secondary error that occurred before this, but was never output - if so, it is likely strongly related to this one, thus fixing this will fix the other.
Composr has detected what may be a hacking attempt. Please do not be alarmed, and unless you are really trying to hack the website, nobody will question you. Please do not click refresh though or you could be automatically banned. If you got here via a link, please inform the link maintainer of the problem.

"Where do I start on all links..." - please be much more specific. The error you posted is a generic error message.

If you go to Admin Zone > Audit > Security Logging you may be able to find a more detailed error message logged in there to report.
A screenshot of the full error details (after clicking on the date to show the details) would help.

A screenshot of where you originally got the error, including the URL, would also help.

Currently I haven't got anything to go on: "all links" could mean anything.

Can not get to admin get the error.

then get added  deny in .htaccess

Can not get to admin get the error.

then get added  deny in .htaccess

Just updated to 10.0.8 and still the same.

Can you do an SQL dump of the cms_hackattack table and post it here or email it to me ([email protected]).

Did you get the email?

Yes, will try and reply today.

It's tripping on "Are you looking to work" being used as some kind of identifier – and because it doesn't look like an identifier it thinks it's a hackattack bot. Do you know where this is used, e.g. is it a manually set  moniker for a news post?

I'm reviewing the code, but it is difficult as I'm not sure where that string is coming from. One possibility is misconfigured Filtercode strings.