Our homes are now full of smart devices, from TVs and
speakers to security cameras. While these devices can make life easier for us,
they're all effective computers running an operating system. Typically,
security hasn't always been of the highest priority for manufacturers of these
devices, opening up the risk that one of these devices will be compromised by
cybercriminals.
Having any device in your home hacked can pose big risks. Take
a camera, for example. If one is hacked, it means that people can spy on you in
your own home. Cameras can be everywhere: even the FBI has warned people to
stick tape over their smart TV's webcams, as it believes that there's a real
risk of these devices being hacked.
The second danger is that a hacked device
can take part in a botnet, performing attacks on other computers on the
internet. We've already seen the example of Mirai, which infected 600,000 loT
devices at its peak, including them in a criminal botnet.
Finally, a compromised device on your home network can be used to probe and attack other
devices, often with greater effect as the outside protection of your router's firewall has already been bypassed.
PLUG AND PREY
Protecting connected devices isn't as
straightforward as it is with a laptop or desktop computer, where you can
install software directly. In effect, you're stuck with any controls that a
device has available on it, and that's it. That doesn't mean you're without
options, however, and we can show you how to make your home network safer.
First, it's important to understand a bit about how devices connect to the
internet. With all home broadband connections, your home has a
single internet-visible IP address (sort of like a postal address). All devices
have to share this using a technology called Network Address Translation (NAT).
When you connect to a service online, such as a website, you use a TCP port
number. For example, standard websites are on port 80, and secure HTTPS
websites are on port 443. When a device makes an outbound request to a website
on port 80, the router assigns a reply port number. Any data that comes back on
that port is sent to the requesting device. In this way, you can have multiple
devices using the same internet connection, without everything getting muddled
up.
Using NAT adds an extra layer of security, too. None of
your computers or devices can be accessed directly from the internet: a random
incoming requests on a random port won't force the router to send data through.
What about devices that need to accept incoming signals from outside, such as a
network camera that you want to control remotely? In this case, you need to set
up a permanent way for this to happen. Port forwarding is a manual option,
where you tell the router where to send data that comes in on a specific port. For
example, you could set up your home to accept incoming connections on port 8080
to go to an internal web server that you're running on a Windows PC on port 80.
Port forwarding can be fiddly to set up, but there's also a technology called
Universal Plug and Play (UPnP). With this enabled, devices inside your home can
automatically configure the router for port forwarding without you having to do
anything. That saves time, but it also means that UPnP can make devices
internet-visible and open to a scan or attack: an attacker can scan your
internet IP address to see which ports respond.
With Mirai, for example, the botnet looked for
internet-connected devices that were vulnerable. It specifically looked for
Linux- based systems, which include many smart devices, and then tried the default username and password to gain access to the operating system, where it
could then take over.
More recently, Hacker exploited a problem with
Chromecast and smart TVs that exposed them to the internet via UPnP, to play a
YouTube video from social media star PewDiePie.
That might not sound so bad,
but what if the hijack played a video that got Alexa to call a number to let a
hacker listen to what's going on, or be really annoying and set an alarm to go
off at 4.30am every morning?
Any device that actually gets infected can then
pose a bigger risk, as it can use UPnP to open up more ports and devices in
your home for further attack.
How, then, do you protect yourself against this
kind of attack? Fortunately, there are several steps you can take. The first is
to disable UPnP in your router. This can stop some devices working until you
manually configure port forwarding, but the extra security can be worth it.
To do this, go into your router's web-based management console
and look for the UPnP setting, which is often buried in the Advanced settings.
With our Netgear Orbi router, the UPnP page has a clear Turn UPnP On tickbox;
removing the tick turns the service off.
UNPLUGGED
The next step that you should take is to audit
the devices you have that are internet-connected, and then work out if you want
to leave them this way. For example, if you have an old
smart TV but you no longer use its smart functions, then you may as well unplug
it from the internet. Do this for everything in your home.
Next, for any device
that you've left plugged in, you need to perform your own security audit. What
you need to do is look at how the device is accessed and controlled, and change
passwords where you can. For example, if you have an older security camera that
you set up manually, are you still running the default username and password on
it? If you are, it's time to change them.
However, this may not always be
possible. For example, smart Ws don't give you the same options, so you're
pretty much stuck with what you've got in the box.
Finally, take a look at your
router to see if it has options for a security that you can turn on. With modern
systems, such as the Orbi, you can turn on malware checking for a month y fee,
which will look out for malicious attempts to hijack or control devices on your home network. Its hard to put a figure on
the efficacy of these systems, but that extra layer of defence will prevent
some attacks happening and gives you that extra layer of security.
CLOUDED VIEW
Many of today's smart devices are controlled via a cloud service, through a
smartphone app. For example, if you're away and turn up your Nest Thermostat,
the request is funneled through Nest's cloud service.
In some ways, this is
more secure than having a direct connection to the device you're controlling,
but what happens if your Nest account (or other accounts) is hacked? This will
then give hackers direct control over devices in your home.
Google has said that this is the result of
a compromised account, rather than a direct attack on its hardware, but it
demonstrates the importance of protecting your cloud account.
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