So you’ve installed an anti-virus program on your PC, you’ve picked the best security app for your smartphone, you never click on suspicious links or open dodgy-looking emails, and you’ve made sure all your passwords are strong — you’re safe from hackers, right? Wrong. Sadly, common attack points like computers and smartphones are just the tip of the iceberg. Thousands of weak points are waiting for hackers to exploit them. Here’s a look at seven of the most surprising:

1. Guns

Guns are pretty scary at the best of times. They’re a whole lot worse when you consider someone could hack them. We’re not talking about handheld pistols or a farmer’s hunting rifle — instead, we’re talking about highly capable and highly dangerous computer-aided sniper rifles. One culprit is the TrackingPoint TP750 precision-guided rifle. In mid-2015, two computer security researchers found they could cause it to miss its target, remotely disable its computer, or turn its scope off entirely.

2. Low Orbit Earth Satellites

We rely on satellites for everything from communications to weather monitoring. As such, it can be disastrous if we lose their capabilities for any reason. However, it’s worryingly simple to hack a satellite. At the Chaos Communication Camp (a security conference) in 2015, organizers gave out 4,500 software-defined radios which were sensitive enough to intercept satellite traffic from the Iridium Satellite Constellation — a network of 66 satellites which provide voice and data coverage to satellite phones, pagers, and integrated transceivers.

3. HVAC systems

Heating, ventilating, and air conditioning (HVAC) systems are an integral part of many large buildings and offices. They ensure there is sufficient air flow, the temperature is comfortable, and air quality remains high. They seem fairly innocuous, yet according to research by security firm Qualys, more than 55,000 HVAC systems “lack adequate security”. Most companies have no idea their HVAC systems are even network-connected.

4. Air Traffic Control systems

With the recent EgyptAir crash in the Mediterranean Sea, plane safety has once again been thrust to the forefront of our collective minds. Although the number of onboard hijackings are way down from their 1980s heyday, the number of hackers taking over air traffic control transmissions and giving pilots fake instructions is growing rapidly.

5.Traffic lights

Traffic lights are the bane of any driver’s life. But did you know that they can be hacked, making that already-miserable commute considerably worse? In late-2014, researchers in America managed to gain access to 40 individual sets of lights in the state of Michigan. Worryingly, they used default passwords and unsecured wireless networks to do the majority of the hacking. The only piece of equipment they used was a laptop.

6. Power grids

The last surprising item on our list is power grids. This may sound like the kind of doomsday scenario that you only see in the movies, but in 2015 it became a reality for residents of Ukraine. The blame appeared to lay squarely at the feet of Russian cybercriminals, with ongoing geopolitical tensions in the region inspiring their actions. At least 30 of the country’s 135 power substations went offline for six hours.

When that happens in the middle of December in a country whose winter temperatures regularly drop as low as minus 20 degrees Celsius (-4 F) it can quickly become an extremely serious problem. According to experts, the Ukrainian system was vulnerable because of its age, though that also allowed it to come back online much quicker.

North American and Western European systems would be much harder to crack, but by bypassing safety mechanisms, hackers could make blackouts last for weeks.