There's a certain kind of security threat that catches the headlines—the massive data breach, or the malware that hijacks your computer for a ransom—but it's also important to keep your guard up against some of the lesser-known attacks out there too.

These threats may not have the same high-level profile as an unfixable iOS bug, but they can still do some serious damage as far as your data and privacy goes. Here's what to look out for, and how to make sure you aren't caught out.

Rogue USB Sticks

A small USB stick may not look very dangerous, but these portable drives can carry a major threat—particularly if they've been specially engineered, as some are, to start causing havoc as soon as you plug them in. You should be very, very wary of connecting a USB drive to your computer if you're not absolutely sure where it's from.

Even if the USB stick isn't configured to release some kind of payload as soon as it's attached, it can carry disguised viruses as easily as email attachments—and experiments have shown that we're often far too curious when coming across USB sticks we don't know the origin of, so apply some common sense.

Besides being cautious, the usual rules apply to stay safe against this sort of threat: Keep your computer operating system right up to date, make sure effective security tools are installed, and keep them updated as well. If you're not sure about files on a USB drive, run a virus scan on them before doing anything.

Zombie Accounts

In this fast-paced, hyperconnected age, it's all too easy to forget about all the social media, language-learning, job-finding apps and sites that we've downloaded and used. But every account you leave behind gathering dust is another one that could potentially be hacked into.

As we've previously explained in detail, it's important to take the time to shut down these accounts rather than just uninstalling the associated app from our phones and then forgetting about them. If any of them should then suffer a data breach, for example, your data won't be included if you've scrubbed the account.

It's also worth running a regular audit on the third-party apps and services linked to your main accounts, like dating apps you might have hooked up to Facebook, or email apps connected to your Google account. These give hackers more targets to aim at, which is why you should regular disconnect and delete the ones you aren't actively using.

Untrusted Browser Extensions

The right browser extensions are able to add useful functionality and features to your daily window on the web, but these add-ons need to be vetted like any other piece of software—after all, they have the privilege of being able to see everything you're doing online, if they want to.

Pick the wrong extension and you could find it selling your browsing data, harassing you with pop-up advertising, or installing extra software that you don't actually want. We'd recommend keeping the number of browser extensions you have installed down to a minimum, and sticking only with the extensions you know and trust.

Identify safe extensions the same way you would identify safe apps: Look into the background of the developers, check the permissions that they ask for, read up on reviews left by other users, and stick to extensions that are actually useful.

Bogus Online Quizzes

You've probably seen friends and family take quizzes on Facebook to find out which Hogwarts house they'd get into, or which celebrity they're most like, and so on. They may seem like harmless fun—and some are—but they can also be used to harvest personal data that you don't really realize you're giving away.