Malware is a word used to refer to a whole range of programs which can cause harm to your computer and computer data. Major malware programs are rootkits and spyware. Key loggers are one type of malware as well as one type of spyware. Of all the known types of malware around we believe that key loggers pose the most danger to your bitcoins.
Key loggers are powerful. They are silent. They evade detection and are potentially the biggest threat to personal home bitcoin wallet storage now and into the future. These pieces of programming which sit silently deep in computer files and operating systems are designed to evade detection and their true distribution in the world may be very widespread or they may be very limited. No one really knows for sure. One thing is for sure though, if you have one on your computer, they are powerful programs and can easily steal your bitcoins.
What a keylogger program basically does is record all your computer keystrokes and other computer input information in a file which is then later sent to or collected by an outside group or person. The information may be sent automatically via email when you go online or collected in some other manner. You can imagine what this could mean to your bitcoins. If an outside person has managed to get a copy of the seed you used to initially create your wallet addresses, they would be able to silently steal from you all your bitcoins for years and years possibly without you even noticing; or they could wait until you had a huge amount of bitcoins and then simply rob you all at once.
The sophistication level of current keylogger programs cannot be under-estimated. They no longer work by just recording keystrokes typed on a keyboard. They can capture whole text copied and pasted from clipboards. They can read virtual keyboard keystrokes. They can take screenshots of your whole computer monitor or just the area around your mouse pointer every time you click. They may be able to record other data about your computer use such as folders accessed and websites visited. If you are using a computer drive which was not just previously formatted and which you did not just personally install a whole new operating system on, then there is always a chance that that computer has a keylogger program in it. On our website for Methods 3 and above we do exactly this to ensure the security of your bitcoin address generation (but in a very quick and simplified process that does not make any changes to your main operating system). Our process when done correctly is absolutely 100% keylogger and malware invulnerable.
For regular computing with your bitcoins on your regular computer operating system though, it is best that you to do an online search-engine search on ways to keep your computer keylogger and malware free and then follow the advice offered from the main websites. The field of data theft and data security is a bit like a never ending arms race between programmers and hackers and so it is always a good idea to get up to date information from reputable websites.