Hackers are always searching for computers that are vulnerable or users who are gullible. There are two main ways they find their way into a computer:
- Hackers can scan every computer address on the Internet and probe each address for the computer equivalent of unlocked doors - vulnerabilities. Once they find a vulnerability, they can probe deeper to see how far they can get in and what they can do with that access.
- Hackers can try to fool you with some "social engineering" scam to get you to open a door for them. They might send "phishing" messages to get your password, or they might construct websites that will deploy malware to take advantage of an unpatched computer.
Once they gain access to your computer they can explore and use your storage as well as monitor your activity to intercept any personal or financial information.
These days, hacking is a business. They are in it for the money. Because most computers have more processing power, memory and speed than you probably need, they can quietly use your computer for their purposes while you use your computer for your purposes. It can be a very long term relationship until their use hurts you in some way.
There seems to be no end of the creativity of the bad guys. Anti-virus software will detect thousands of virus programs that have been discovered and analysed by the good guys. But a new virus is not detectable until someone has been victimized and reported it.
Likewise, spam filters will block known hazardous spam, but not the new stuff until some victims have reported it. And new patches aren't released until after someone discovers a new vulnerability. If the bad guys discover it first, then the first victims will report it and the programmers will work on fixing it.
If you have installed all patches and updates, updated your virus protection and have a good spam filter, your risk is markedly reduced. There are so many computer users who are not diligent about these things, that hackers have plenty of targets. Don't be one of them!