We’ve unfortunately reached an era where a phone in every pocket isn’t just a luxury, but a necessity. Hackers know this and therefore have a guaranteed attack vector. Meanwhile, phones, while improving in resources all the time, are sometimes less secure than a desktop computer, based on raw number-crunching power.
Here are some warning signs that your phone might have been compromised:
Unusual activity on linked accounts
This is the easiest to spot. Do you see posts on Twitter you didn’t make, bank account transfers you didn’t authorize, or emails in your history you didn’t send? If your phone is compromised, somebody else has control of every account you have linked from it.
Sudden increase in pop-ups
Adware and Spamware are the most common infecting malware on a phone. This will manifest in constant notification pop-ups, your web browser (e.g. Chrome) being redirected to a spam page, new applications suddenly installing themselves, and general busy activity on your phone without you doing anything.
Mystery outgoing texts and calls
Infected phones usually attempt to spread a virus through your contact list. Your phone will suddenly send messages to everybody in your address book. Check your record of outgoing messages and look for anything you didn’t send. Of course, if you have a wide range of contacts, several of them might message you back asking what the strange message was all about, which is another warning sign.
High data usage
Normally you’d be keeping your phone connected to the nearest WiFi, only using mobile data when you’re on the go. Some apps ask to use mobile data as well. You should be able to account for most of your mobile data bandwidth. If you’re seeing gigabytes of mobile data being burned up in a matter of days without you having done anything unusual, that’s a red flag.
Decreased system performance
Viruses running in the background suck down system resources. This is one advantage that a phone has over a desktop computer, however, since even minor activity in the background makes a noticeable bump in performance on a phone. If your phone isn’t all that old – realistically, most people upgrade every five years or so – but is slow to respond and crashes or freezes often, this is a sign that something in the background is hogging all the system resources.
Sharp decrease in battery life
All phone batteries charge a little slower and run down a little faster over time, but normal wear and tear will only mean a 2-3% difference. When your phone is infected, it might chew through your full charge in a matter of hours even when you weren’t using it.
In addition to the above, the following is the most likely attack vectors on your phone. If you’re experienced any of these recently, one of them could be the cause.
You’ve installed an app that demanded full access permissions
Apps should have a logical reason for needing access to your camera, social media accounts, or other resources. Almost no legitimate app needs to access everything.
You’ve received “fishy” messages
“Phishing,” as it is properly called, is the act of spoofing another entity while sending you a false email, text, or call. For example, a message claiming to be from your bank and needing your account information is likely a phishing attempt. We don’t all pay attention to every message we receive, so it’s easy to just handle a pop-up and dismiss it without thinking sometimes.
You’ve used unsecured public WiFi
Not every open network is a good idea to join. If you’re at a restaurant and the company has an official guest log-in, that’s different. But a strange WiFi signal appearing out of place with your surroundings could be a network which is sniffing your data as you use it, maybe even logging passwords as you use it.
What to do?
If your phone has been hacked, you’ll need to stop using it at all until you get the system cleaned, updated, and protected by an anti-malware app. Disable WiFi, Bluetooth, and GPS in the meantime. If your bank or other financial data might be compromised, check with your bank through a non-infected communication method to block unauthorized charges.