On TV, computers seem to have a record of everything that happens on a computer. What files where copied, what files were access, and so forth. In the real world, that’s simply not the case. Sometimes we can figure out how an infection got in, but most of the time we can’t. And nobody ever wants to pay extra for us to spend the time to find out, so we never get to try.
Speaking in general terms, however, we can tell you how infections usually get on your computer.
- Infected Website
This is how most infections get on your computer. There are several ways that someone can end up on an infected website, but usually they either did a search on a search engine (like Google) or clicked on a link in an email. Once you are there, the infected website may use several different methods to infect your computer. They may take advantage of a security hole in your browser or in Windows, or they may try to trick you into downloading the infection.
- Infected Advertisement
This is similar to the infected website except that the actual infection isn’t on the website. It’s located on the advertising service that the website uses. The owners of the actual website aren’t the ones trying to infect your computer. The ad service they use is either shady or, more likely, has been hacked.
- Email attachment
This is pretty self explanatory. An infection arrives attached to an email. If you open the attachment, it will attempt to infect your computer.
- Network attack
A direct attack is less common these days, but certainly still happens. An automated program tries to break through your firewall (if you have one) to attack your computer over the local network or over the internet.
- Personal Attack
If someone gets physical (or remote) access to your computer they can intentionally infect it. Not very common, but it does happen. Especially in cases of divorce. One spouse may put spyware or remote access software on the other’s computer.