Unwanted ads account for 72% of mobile malware: Avast cybersecurity

Adware or software that hijacks a device in order to spam the user with unwanted ads now accounts for 72 per cent of all mobile malware, says a new report from cybersecurity firm Avast.

The remaining 28 per cent consist of banking trojans, fake apps, lockers, and downloaders, according to statistics gathered by Avast's Threat Lab experts.

The data showed that the share of adware among all Android malware types increased by 38 per cent in the past year alone.

"No one likes getting served with incessant ads; they're often unwanted and can ruin our enjoyment of an app. They could also pose a threat to users as cybercriminals can use them as a backdoor to a device - whether it's to make money from advertisers or steal your personal information," Nikolaos Chrysaidos, Head of Mobile Threat Intelligence & Security at Avast, said in a statement.

"We've been tracking this issue for a number of years and the increased use of mobile devices is likely fuelling its growth," Chrysaidos said.

Adware often disguises itself in the form of gaming and entertainment apps, or other app types that are trending and therefore are interesting targets with a high potential to spread far.

These apps may appear harmless, but once they have infected a device they will surreptitiously click on ads in the background. Sometimes, adware also serves ads with malicious content.

There are two main types of adware: adware apps, which cause distraction and annoyance; and ad-fraud/ad-clickers, a more malicious type of adware.

To prevent mobile adware attacks, users should only download apps from official app stores, like Google Play, as they have security measures in place to check apps before developers upload them, or from the app's website directly for extra assurance, Avast recommended. It is also important to carefully review the permissions an app requests before downloading an app.