We introduce you to this year's batch of security vulnerabilities to watch out for.

Online malicious activity was a major headache in 2010, and so far, 2011 is no different: We've seen scams and malware on Twitter, Facebook, and the Android Market, as well as a rise in politically motivated online attacks.

But that's no surprise to security experts such as Graham Cluley, senior technology consultant for security firm Sopho. Cluley says that Sophos analyses about 95,000 pieces of malware every day that is either brand-new or a variant of an older attack.

The bad guys are hard at work figuring out new ways to infect your system. The good news is that the latest antivirus programs do a better job than ever at detecting suspicious activity before it can damage your computer.

But security software can't always protect you; sometimes the best defence is a dose of common sense and a little bit of knowledge about what to watch out for. Whether it's fake antivirus scams, malware on social networks, or good old-fashioned email attachments loaded with viruses, it pays to be on your toes so you don't end up becoming a victim to identity theft, a raided bank account, or even a home invasion.

So here's a look at 2011's five big security threats, and the steps you can take to avoid becoming a victim.

NEXT PAGE: Mobile apps

  1. Vulnerabilities to watch out for
  2. Mobile apps
  3. Social network-based scams
  4. PDFs