MOSCOW, August 6 A slowdown in the operation of a smartphone, frequent overheating, uncontrolled changes in GPS, Wi-Fi or mobile data settings may be signs that the device is infected with malicious software, said the deputy director of the NTI Competence Center «Trusted Interaction Technologies» at TUSUR base Ruslan Permyakov.
«Signs of infection: … If your phone has become unusually slow, quickly discharges its battery, or overheats, this may be a sign of malicious activity … Uncontrolled changes to device settings, such as GPS, Wi-Fi, or mobile data, may also indicate the presence of malware,» Permyakov said. 
He added that a sharp increase in the user's mobile phone bill without changing their network usage habits or the appearance of new applications on the device that the user did not install could also indicate that malware is running in the background.
The expert reminded that it is worth regularly updating the operating system and applications, using antivirus software, and downloading applications only from official sources such as Google Play or the App Store.
He also recommended being careful when using Wi-Fi, using virtual private networks (VPNs) to protect data when using public networks, and regularly backing up data.