The use of aggressive ad networks inside free apps has increased by 31 per cent in nine months, according to new research by Norton.
Dubbed ‘madware’, some aggressive ad networks have been known to place advertising in a device’s photo album and calendar entries.
Mobile adware can disrupt user experience and potentially expose location details, contact information and device identifiers to cybercriminals.
Norton reports that on average, a quarter of all apps monetise via ads and that 49 per cent of those use the most aggressive ad networks.
The security firm has launched a free app called Norton Spot, which is designed to let mobile users enjoy free apps without the malware that comes with them.