Attacks involving mobile banking Trojans on smartphones increased 56% in 2025 compared to the previous year, according to a recent cybersecurity report. Designed to steal banking credentials and payment information, these threats show how a compromised smartphone can put more than personal messages and photos at risk. Access to a single device can expose financial accounts, passwords and sensitive information that criminals may use to commit identity theft.
Patrick Glennon, who leads technology and security at IDIQ and its IdentityIQ identity theft protection service, has more than two decades of experience in banking and consumer identity protection. In a recent IdentityIQ guide to recognizing the signs of a hacked phone, Glennon outlines the warning signs consumers should watch for and steps they can take to protect their personal information.
Glennon says consumers should pay attention to suspicious account activity and unexpected changes but avoid jumping to conclusions based on everyday phone problems.
“One symptom alone does not prove your phone is hacked,” Glennon said.
Warning Signs of a Hacked Phone
A phone running slowly, overheating, or losing battery life can be frustrating, but these issues often have ordinary explanations, such as aging batteries, software updates, and apps running in the background. More concerning signs involve activity that the owner does not recognize or authorize.
Some of the strongest indicators of a potentially hacked phone include:
- Unrecognized account logins: Unknown devices or sign-ins connected to an Apple Account, Google account, or email account may indicate unauthorized access.
- Unfamiliar apps or permissions: Applications, configuration profiles, or accessibility permissions that you did not install or approve deserve attention.
- Messages or calls you did not send: Texts, emails, calls, or social media posts made without your knowledge may point to a compromised device or account.
- Unexpected purchases or verification codes: Unfamiliar charges, password-reset notifications, and authentication codes you did not request can signal attempted account access.
- Unexpected loss of phone service: An unexplained interruption may be a sign of a SIM swap, which occurs when a criminal transfers a victim’s phone number to another device.
- Unfamiliar access to your phone’s camera, microphone, or location: Review which apps have permission to access these features and investigate anything you do not recognize.
- Suspicious browser behavior: Unexpected advertisements and redirects can indicate adware or suspicious applications.
- A noticeable increase in cellular data use: A sudden spike in background data activity may warrant a closer look at installed apps.
The key is to look at the full picture rather than treating every unusual behavior as proof of a security breach.
“Multiple related signals matter more than any single issue. Performance problems alone are rarely evidence of hacking,” Glennon said.
How Hackers Gain Access to Smartphones
Cybercriminals use several methods to compromise phones and the accounts connected to them. One common tactic is SMS phishing, also known as smishing. These fraudulent text messages often appear to come from banks, delivery companies, or government agencies. A link may lead to a fake login page designed to steal passwords or financial information.
Malicious applications are another potential entry point. Apps downloaded from unofficial sources, as well as lookalike apps that request unnecessary permissions, can expose sensitive information. Reusing passwords across multiple accounts creates another opening for cybercriminals. If criminals obtain a password from one breached service, they may try it on email, banking, and social media accounts.
SIM swap scams can be especially damaging. By convincing a wireless carrier to transfer a victim’s phone number to a SIM card they control, criminals may intercept calls and text messages, including verification codes used to access financial and other online accounts.
Outdated software also leaves devices exposed. Phone operating system and application updates often include security fixes that address known vulnerabilities. Delaying those updates can give attackers opportunities to exploit weaknesses that have already been identified.
What to Do if Your Phone Has Been Hacked
If a phone may be compromised, consumers should focus first on securing their accounts and limiting further access.
Start by securing the primary email account and Apple or Google account. Review connected devices and recent sign-in activity, remove unfamiliar sessions, change affected passwords, and enable stronger authentication. Unique passwords and passkeys or authenticator apps can help reduce the risk of unauthorized access.
Consumers should also contact their bank or card issuer if they find unfamiliar transactions. Anyone who suspects a SIM swap should contact their wireless carrier immediately to regain control of the phone number and add an account PIN or other security protections.
Review credit reports for unfamiliar accounts, address changes, and other unauthorized activities. If personal information may have been stolen, consider placing a fraud alert or credit freeze with the major credit bureaus.
Why Phone Security Is Also Helping Protect Your Identity Protection
A compromised phone can expose information that criminals may use long after the initial incident. Even after a device is secured, stolen personal details can create ongoing risks for financial accounts and identity security.
“A phone is not just a phone anymore. It holds your banking apps, private messages, photos, email, and the authentication codes that protect your other accounts,” Glennon said.
That connection between mobile security and identity theft makes it important to monitor more than the device itself. Consumers should review financial activity, check their credit reports, and watch for signs that exposed personal information is being misused.
Identity theft protection services offer additional tools for monitoring potential threats. Top-rated IdentityIQ provides identity protection features that include dark web monitoring, credit monitoring, real-time fraud alerts, device protection, and identity restoration support.
As mobile devices are now closely tied to consumers’ financial lives, recognizing suspicious activity and responding quickly, along with adding another layer of protection with an identity protection service, are essential steps in reducing the risk of identity theft.
