[Exim] exim subject filter in 2.12

I'm running exim 2.12, yes I know it's an old version, but hey.. it works.

There's a "virus" a VBScript that's looking like it's going to go
exponential.

How can I filter out any message going through the server with subject of
"ILOVEYOU" so that it gets immediately binned?

Cheers,
Matt.