Electrum, a popular desktop wallet, has had a security vulnerability that has recently been patched. Anyone using Electrum needs to patch the update! One thing to definitely consider, however, is purchasing a hardware wallet once your holdings get to a sizable amount.
Also enable 2 factor authentication on EVERYTHING! All your exchange accounts need to have 2-FA, ideally on a tablet that isn't connected to a wireless network. It would suck to lose a significant part of your crypto due to convenience or trying to save 100 USD from purchasing a hardware wallet.