As our daily lives are increasingly spent on our smartphones, there will of course be times where we recognise some faults with our beloved devices. However, it can be difficult to identify when these faults are a sign of being hacked as opposed to a software glitch or general wear and tear from use.

Personal information such as banking details and social communication are now within immediate reach on our devices, so it's important to keep them secure.

Yet people tend to be less wary on their handhelds surrounding malicious applications or software updates, prompting hackers to target handheld devices. 

Here, we reveal some warning signs that your smartphone is being hacked. 

Read next: Best secure messaging apps.

Background noise


If you start to notice background noises, whether, during phone calls or whilst listening to audio, it could be a sign that your phone may have been hacked.

It could be that someone may be intruding in your conversations, or has been able to get into your phone as a result of a software or hardware glitch that may have occurred.

It is worth regularly checking your phone to keep up to date with any malfunctions, while also making sure that regular updates are made as these could fix any glitches.

Understand your operating system


At first, it appears Apple users have a sweeter deal when it comes to security. Apple’s iPhone system works on closed source software, meaning iOS filters applications and updates keeping the develops core features permanent.

Where as Android is open source, allowing for full customisation. This is thought to be less secure as malware is not automatically filtered, however, it also keeps the Android platform transparent.

Make sure you are taking the necessary security precautions relevant to your OS. 

Your battery isn't lasting very long


If you begin to notice that your battery is needing to be charged more frequently, it is normally down to something running in the background on your device. 

In more sinister cases, it is because you have downloaded some sort of malware which is running in the background and slowing everything down. 

This is not good, as - depending on what kind of malware it is - you could become victim to anything from identity theft to the seizing of your documents.

Also, if your phone starts to heat up a lot, this could indicate a problem with the battery. It may mean that the battery is no longer strong enough, which could also lead to the battery not staying charged long enough.

If you regularly use social media apps or play games on your phone, this opens doors for hackers to get in through spyware, also potentially causing the battery to drain.

Your data usage has increased


Another thing to watch out for is your data usage. Most of us will average a set amount of data that we will use a month, mainly because we do the same things on repeat each month online. We are animals of habit after all. 

If you notice that your data usage has increased or even that you're surpassing your allotted data allowance, your phone may have been compromised by some form of malware. 

An increase in data usage could indicate another device transmitting data from your device to its own. 

Delete any new apps you've downloaded and contact your phone contract provider. If all else fails, do a reset of the whole phone.

Phishing


The most varied and successful of the hacker's tools, ‘phishing’ is where someone pretends to be a trusted other or a company to gain access to your personal information.

Seen often in the form of emails, this method can be hard to detect, but there are key indicators that reveal you are being baited.

Typos, grammar mistakes, and an overuse of punctuation such as exclamation marks are an immediate red herring. Differing email addresses or an impersonal introduction are also fraudulent signs, as banks and airlines try to be as personal and transparent as possible.

Embedded forms, strange attachments and alternative web links are also suspicious. Ignoring these suspect emails and their frequent sudden deadlines is a good step to not being netted.

Public Wi-Fi


Another popular way hackers are able to access your personal information is by utilising your phone’s Wi-Fi connection to a public hotspot. 

Connection to public Wi-Fi is unencrypted and hackers use various techniques to gain admission. They could present you with a fake site where you are asked to enter your details. This can be very convincing and difficult to detect so we recommend you never use mobile banking or shopping over public Wi-Fi.

Hackers could set up a fake access point (AP) with free internet available, often taking the name of a genuine hotspot. Advice to stop this is, before connecting, if you see two similar network connections do not connect and alert management of the offering establishment.

If you've joined a Wi-Fi network you're not familiar with, it could be corrupted. Monitor the look and feel of the interface. If it contains a logo that is slightly different to the once you're expecting to see or has typos and inaccuracies, you could be on a false Wi-Fi network, pretending to be the official one you're after.

When using public Wi-Fi always remember to sign out afterwards, if you leave without doing this a sidejacker (session hacker) could continue your web session on site you’ve used such as Facebook or your emails. They do this via cookies and HTTP packets, so always remember to sign out, ending your session when you’ve finished.

Bluetooth


Bluetooth can allow a hacker to access your phone without even touching it. This form of hacking can also go unnoticed by the user. It can infect other devices surrounding you if they also have their Bluetooth switched on.

Last year, security company Armis identified a new attack called BlueBorne which collectively used Bluetooth to gain unauthorised access to mobile phones.

It affected almost 5.3 billion devices and allowed attackers to take control of devices, access corporate data and networks. Armis reported half of the attacks were critical with devices only needing their Bluetooth active for attackers to gain access and spread malware.

Switch your Bluetooth off and be aware of any suspicious downloads or URL links in text, emails and messenger services, such as Facebook or WhatsApp, which can disrupt and damage your phone.

If you notice your Bluetooth is on and you didn’t turn it on, switch if off and run a scan.

Software


Popup updates from third-party programs can not only be annoying, but also lethal for your phone. They can use your admission to install dangerous malware and spyware so it's important to be able to spot and avoid them.

Real software updates always come from the publisher's original website, any links to alternative sites should be deemed fraudulent. The link’s authenticity can be easily checked by viewing the sites HTML address. Free software services should never send email alerts for an immediate update, and in their notifications will always have ‘check’ or ‘review’ option.

Again, if the look and feel of the software update doesn't seem right, it probably isn't. If it asks for any personal information or requires an additional login, it could be a malicious software update. 

Apps


There are a lot of fake apps available now that could cause unwanted problems, such as spyware or virus infestation. They could include intrusive pop ups, ask for personal information or be difficult to delete. Therefore it is key to be able to spot a fake app before it can do damage to your device.

When selecting, pay attention to the app’s details; reviews, publisher, logo, amount of downloads and ‘editor’s choice’ tick should give an indication of its legitimacy.

Searching the application online first to see if a legitimate mobile variation exists is wise, as well as cross-referencing the app’s publish date. When browsing the store’s website, there is usually a link to their official app enclosed.

Many fake apps, like those for betting or shopping, offer discounts or deals to draw you in.

Mobile data


Some organisations, have introduced ‘bring your own devices policy’ (BYOD), however, this has created major security risks through employees connecting to open networks and using poor passwords.

Monitoring your activity from apps, online browsing and emails can detect if your device may be infected. A great way to detect your phone activity is through data.

Most network providers and phone settings give a detailed breakdown of the sites used and data consumed.

If you see a greater use of data than before it may be a sign that malware is transmitting data from your device to third parties.