If you ever used the payment protocol (you clicked a bitcoin: link and saw a green box in Bitcoin Core's send dialog), then you should consider your wallet to be compromised.

This vulnerability is caused by a critical bug in the OpenSSL library used by Bitcoin Core. Successfully attacking Bitcoin Core by means of this bug seems to be difficult in most cases, and it seems at this point that even successful attacks may be limited, but I recommend taking the above actions just in case.