Avast antivirus, its free, works well and it doesnt use much memory in my experience.
Unfortunately, there is no such thing as a 100% secure website…even the gov and military get hacked. Just comes down to common sense of keeping backups but only put information in your account and other websites that is “needed”. For passwords, I use 12 to 18 alphanumeric characters with a mix of symbols as well…But I know that it’s also the responsibility of websites that we go to, to ensure they follow a good level of security, but as I said, there is no such thing as a 100% secure website. One thing too…for themeforest and money earned, try not to keep your funds in it. Unfortunately Envato only pays out once each month, but you have to also time it right or you will be waiting up to a month and a half to get paid out. Would be nice to have a bi-weekly payout schedule where you don’t have to wait until the following month. This would help lessen the possibility of hacked accounts taking your funds.