When you feel you attacked by a keylogger, is your computer aways running? If so, you may check if there is " /var/log/kernel.log", if there is, you may sneak attacked by keyloggers.
You also can install an anti-keylogger softwarel to check if there is a keylogger on your PC.
Before you sure the problem, recommend you change your important password with virtual keyboad which can not be recorded by keylogger.