Smaller cryptos have always followed BTC, it's just more pronounced recently. That's why I've stopped trading cryptocurrencies - instead I perceive them as a single refuge in times of fiat currency crisis (just as gold is).

If I am not mistaken, the latest ransomware used BTC as payment, right? This certainly raised the price of Bitcoin. And what better way to hide your tracks, but to convert your illegally obtained cryptocurrency into its alt siblings?