Top 10 security threats that could ruin your day

Let's face the facts, people – the world has become a pretty scary place. In the salad days of your youth, all you had to worry about was the health and well-being of your family and locking your doors at night. Not anymore.

Today, you need to worry about security in a whole different arena: Your PC. Spyware, viruses and Trojans are lurking online, waiting to infest your computer. All could easily cripple your PC if you're not careful. Worse yet, hackers could steal important personal information – there are all manner of threats out there.

In this article, we’ll look at the top ten security threats, and rank them in order of how dangerous they are. We’ll start at number ten, and count down to number one… just for a little bit of suspense.

10. Spam email

While it's annoying, it's not a security threat unless it comes with a malicious payload. Your email service may filter out spam automatically. If not, Outlook's built-in junk mail filter is effective, or you might get anti-spam protection with your security suite.

9. Phishing email

Phishing messages pretend to be from eBay, PayPal, your bank, or the like. If you log in to their fake sites, they steal your username and password and you're sunk.

8. Wireless attack

If you're not careful, anybody in range can mooch bandwidth from your wireless network and can rummage through your files, because they're inside your network. Your router's WPA2 encryption can stop the mooching – but you have to use it. See our 10 tips to help secure your wireless network for more details.

7. Hacker attack

Hackers don't care about your puny computer enough to attack it directly. They might broadcast a network virus or release a Trojan, but a personal attack is highly unlikely. Still, you might see such an attack in your workplace, for example – check out our tips on avoiding a targeted malware attack for more details.

6. Web exploit

Some websites include malicious code to exploit vulnerabilities in your browser or operating system. Just visiting the site can infect or damage your system if the vulnerability hasn't been patched, so keep Automatic Updates on.

5. Adware/Spyware

Simple adware pops up ads that get in your face. That might not sound too bad, but some adware threats can blast you with so many adverts, the PC becomes barely usable. Spyware spies on everything you do and steals private information.

4. Virus/Worm

A computer virus spreads by injecting its code into other programs or, less commonly, into the boot sector of a disk. When you execute the infected application, the virus code runs too. It may simply infect more files, or it may perform a "payload" action like wiping out your hard drive. A worm replicates itself like a virus, but it’s different because it doesn't wait for you to launch an infected program. Network worms can spread around the world like wildfire. If you’ve got a good antivirus program, you should be safe here, of course – but nothing is 100 per cent perfect in terms of protection.

3. Trojan

Trojan horse programs pretend to be useful but can turn your computer into a spam-spewing zombie, or worse. Some Android Trojans, for example, can send texts to premium SMS services and run your bill up.

2. Identity theft

It's not just about your computer when they use your credit cards or plunder your bank account. A full-powered security suite should help to block all computer-related avenues for identity theft – but you’ll need to use your common sense to avoid it, too. See our guide to preventing identity theft for more.

1. Social engineering

And speaking of common sense, the number one threat to your computer's security is – you! Use your common sense at all times! Don't accept and run programs from strangers, don't go to iffy looking websites, don’t assume that a link in an email is automatically safe because a friend sent it to you, and if your security software pops up a warning, READ IT before you click.