Noticed weird things occurring on your smart device or people you interact with having knowledge they shouldn’t? Unfortunately, your phone or tablet might be hacked. More precisely, the SIM card in it. This can mean the one you can insert, such as a nano-SIM card, and the one that’s soldered, e.g. an embedded SIM card. Whoever has access to it, no matter whether physical or halfway across the world, can listen to your calls, see your texts, and track your location. Even worse, the consequences can be devastating to your life if the culprit has evil intentions in mind. To set your mind at ease, we’ll answer your question, “how to know if my SIM card is hacked?”
Why are SIM cards desirable to hackers?
There are 3 common reasons that a SIM card is attractive to hackers:
Although it’s never right, the degree depends on the perpetrator. If it’s a curious partner that need to satisfy their curiosity or verify there’s no reason for doubt, it could be quick and harmless. But if it’s severe, it’s not only creepy but can be life-threatening and cause a lot of stress.
Some people get off on stirring drama and can’t stop at spying. So, they start replying to texts or calling or receiving calls in place of the owner. Once again, this could be a harmless prank or a malevolent act.
3. Clout or profit
Hackers sometimes don’t care about texts, calls, or location. A solid example of this is Jeff Bezos’ May 2018 phone hack or Twitter’s CEO, Jack Dorsey’s September 2019 account hack. It was done by a highly-skilled group of individuals that sought notoriety and money through blackmail. For a regular Joe, the most common example is hackers bypassing two-factor authentication or calling/texting/browsing the Web on your dime.
What are popular SIM card hacking techniques?
These are 3 common SIM card hacking methods:
1. SIM card swapping
No, it’s not the type of swapping SIM cards you think of. Instead, it’s a refined method where hackers call your SIM card carrier and pretend they’re you. But how do they confirm the identity? Well, they get your information through phishing, spyware, social engineering, or bribe the customer service representative. Then, they switch the phone number to the one they own.
2. SIM card cloning
We already wrote a how to clone a SIM card guide. It involves using a SIM card reader and a blank SIM card to duplicate the contents of your card. The person tricks the network and starts receiving everything you do on your phone.
3. Spyware and phishing
The hacker can either plant a piece of code, use a backdoor, install a spying app without your knowledge, or trick you into installing spyware remotely. This doesn’t affect the SIM card directly, since you can still remove the SIM card and destroy it. However, the spyware can interfere with you inserting a new one. Even if it allows it, it can immediately transfer over to any new SIM cards you slide in or activate.
8 signs that your SIM card is hacked
Now that you know what tricks hackers have up their sleeve, let’s talk about symptoms. Here are 8 indications that someone hacked your SIM card:
1. You gave your information away recently
Yes, we’re aware this isn’t enough for a conclusion. However, it can get the ball rolling on your event recollection. Have you filled a survey, whether online or in real life? Did you give out your details, including your phone number and PIN, for whatever reason? Have you had to call for tech support or customer service? Try to remember – it doesn’t matter how reliable and well-intentioned the person felt. You didn’t even have to do it manually. Installing shady apps, especially for rooting or jailbreaking, can do it for you.
2. You stopped receiving calls and texts and lost Internet access
Unless your operating system started acting up or your contract expired, this is a great indication of SIM card swapping. Restart your smartphone to check if it persists. If it does, call your carrier immediately.
3. New entries in your address book, messages, gallery, or call history
Except for the cases of large families, friend groups, or multiple phone users, this can be a dead giveaway of hacking methods 2 and 3. Also, if those unknown entries disappear after a time, it’s most likely the hacker trying to cover its tracks.
4. Pop-ups, slow-down, new apps being installed or antivirus apps removed
Of course, all of these could be manifestations of a malware infection, which is dangerous in its own right. And, although hard to distinguish, the solution is the same – get rid of it.
5. Weird notifications, alerts, codes, or lost password requests
Started getting authentication codes or links to reset lost passwords? What about notifications (supposedly) from your carrier or services you use? They could ask you to confirm your identity, provide details for a free upgrade, or even pretend to offer a refund. These are well-known traits of SIM card hacking and you have to act quickly.
6. Unusual or impossible locations, abnormal data usage
If you’re using apps such as Find my iPhone or Android Find My Device, take a look at the locations your phone has been in. Doesn’t match with the locations you resided in, and you’re not using a VPN? It could mean that someone else has access to your SIM card and phone. At the very least, the phone has been sending data over the Internet or network behind your back.
7. Atypical account activity
For online banks, check your transaction history and account balance. Accounts for services such as Apple, Microsoft, Google, Facebook, or Instagram typically mail you a warning that someone logged in on an unrecognized device. Be aware that the scammers can delete those if they have spyware access. Additionally, any subscription service or your TV/Internet provider will mail, text, or call about suspicious activity. If it progresses, your contacts might start receiving e-mails or texts from your accounts, while they don’t appear on your side. The worst-case scenario? You suddenly get locked out of most, if not all accounts.
8. Battery drain and increase in heat
Unless your battery is old, faulty, or not calibrated, this can be a good way to tell your SIM card was hacked. All the data sending and receiving ups the power usage, using battery reserves and causing the phone to heat up. Hackers can also change the command for your power button to one for low-power mode so that it never powers off. Those with physical access can install a capacitor to truly make sure you can never cut the electricity off, even if you remove your battery.