Zero Day. If it sounds serious, that’s because it is.

“You have zero days to respond to that threat… that’s where something has been released, there is no known defense, no known patch,” explained Dr. Chris Pierson, CEO of BlackCloak, a company that provides security defense for high-net-worth individuals and executives.

“Those are going to be the biggest of the big, the most known vulnerabilities.”

Zero Day security issues recently happened to the iPhone, Google’s Chrome web browser and the Windows operating system.

It means that software companies need to scramble to release a fix. Otherwise, hackers can use the vulnerability to their advantage.

“They’re going to be targeting people that work in the intelligence sector, people that work in government journalists, corporate executives, people that work for defense industrial based companies, those are the individuals that are most at risk,” said Pierson.

But everyday people can also be affected.

“It happens all the time, it happens more often than you would realize,” said Steve Tcherchian, Chief Information Security Officer at XYPRO Technology, a company that provides security software to financial institutions.

“You’re not going to be able to work, you’re not going to be able to make phone calls, your files could be locked potentially forever, your kids’ pictures, all of that is in play,” said Tcherchian.

Hackers don’t even need to target you specifically. A website you visit could deliver malicious code to your devices.

The best way to keep this from happening is simple: update your software.

“From your router to your smart devices your kids’ computers your kids’ phones, iPads, all of that needs to be continuously checked and updated…it might seem like a tedious task but I’m telling you the alternative is not worth it,” said Tcherchian.

Steve Tcherchian, Chief Information Security Officer at XYPRO Technology

On the iPhone, Android, Mac and PC, there are two places to check – both the operating system and the app store. Be sure to back up any important files before you do any updates.

iPhone: Go to Settings > General, then tap Software Update.

Android: Go to Settings > Software update

Mac: Click the Apple Menu in the upper left-hand corner of your screen, then choose About This Mac. Next, click Software Update.

Windows: Search in the taskbar for “update,” then choose Check for updates. Tap Check for Updates again.

Chrome: Tap the three little dots in the upper right-hand corner of the screen, then hover over Help, then click on About Chrome. Chrome will check for any updates. Restart to install them.

For a more hands off approach, enable automatic updates, which typically occur overnight.

“Installing those updates will ensure you’ve got the latest version of the software and any vulnerabilities that they’re aware of are properly patched and addressed so they can no longer be exploited,” concluded Tcherchian.

Many people don’t install these updates because they don’t like it when features or settings change. That’s understandable, but at the very least, be sure to install any critical security updates, even if you don’t upgrade the entire operating system.