It's a good question, really. Where did the ol' computer virus go, and what's all this new crap people are talking about? Honestly, the term 'computer virus' has been so overloaded and misunderstood in the last decade that it doesn't really mean much anymore. In the same way, the method of doing nefarious things with people's computer has also changed pretty drastically in the last decade. Where we used to have a generic 'computer virus' we now have many different naughty programs exploiting people, depending on the purpose of naughty program. Not only that, with the improvements in antivirus software and operating system security, (please queue any dramatic music you happen to have nearby) we're the ones infecting our own computers.
That is correct! Given the current nature of the world, most of the computer problems we have are self inflicted. Not in the 'well you shouldn't have gone to that site' sort of way. In the 'you specifically downloaded and installed a program that is bad news' sort of way. Rogue antivirus, ransomware, and adware are some of the more common types of nefarious programs you might encounter, and the ones I'll mention specifically in this article.
The Types of Threats
Rogue antivirus (also called Rogue Security Software) is a nefarious software that disguises itself as a real software. An example is a software that a website describes as something that would help you remove viruses or protect against threats, but in reality it does quite the opposite.
Ransomware is a nefarious software that will make its way onto your machine in various ways. In its benign version it'll simply claim to require payment before it can remove a virus or other unwanted item (which often doesn't exist). In its more extreme version, it'll encrypt a bunch of your data and then demand payment before it'll provide a method for you to decrypt your data and make it usable again.
Adware is a nefarious software with the specific goal of popping up ads on your computer (sometimes they'll pop up on websites you visit, making it seem like it's a website doing it). While this isn't necessarily damaging, it generally does hinder performance, and it's definitely not good for computer usability. Even with that aside, Adware generally doesn't travel alone. Whatever brought in the Adware normally brings in friends as well.
The Ways The Threats Get In
Some unwanted software ends up being directly downloaded, normally by tricking the user by claiming to be something it's not. Other times, a software is intentionally downloaded but, due to dishonesty or chicanery, they bundle in another, more shenanigans-based software along with it.
Disguised as Another Software
Some big bad jerks try to infect you by either tricking you into thinking their software is a legitimate software, or taking a legitimate software and packing some naughty stuff into it before offering it to you. In the latter case, you'll get the software you expected, but also another super-secret software that you did not want.
Bundled With a Legitimate Software
Sometimes legitimate software will bundle additional software that you didn't want. This software isn't always nefarious in nature, but it's not something you wanted. The primary example of this is a software that has an installer where they offer you software from their 'partners'. These partner software can be skipped, but they're chosen by default and are often missed as people mash the 'next' button trying to get the software installed. Even worse, these 'partners' are simply another company (or individual) who was willing to pay a few dollars to get their software placed in the installer for another software, not actual partners.
How to Protect Yourself
So, you're probably wondering "okay, how do I protect myself?" Well, it's really just about being mindful as you browse the web, and when you download software. It's important to keep in mind that there's no free lunch. If something seems too good to be true, it quite likely is. For example, if the site offers copyrighted content for free (which is all but guaranteed to be illegal, unless it's the copyright owner's own website), the site owners are definitely unscrupulous, and clearly don't care about morality or anything of the sort. They care only about putting a bit of coin in their pocket.
I hope this brief overview of a few of the threats we face in today's world helpful, and I'll see you next time.