Recently, I've had both my Visa debit then my Visa credit cards compromised and unapproved payments attempted to be made on them (my bank caught them first, called me then stopped my cards). These occurred approximately 3 weeks apart.
I'm fairly paranoid about online security so I use LastPass and PayPal is directly hooked into my bank account.
I also changed my LastPass master password after the first breach and ran a full Spybot & NOD32 scan of my computer, with no adverse results.
Now that I've had another breach on a different card, I'm concerned about other things hiding on my computer or something else.
What steps should I take now that I've been compromised again? Should I do a full OS format of my computer? Is there anything else I can do to mitigate the chances of this happening again?