Avast's mobile threat team identified 2021’s biggest Android threats, and adware takes the cake

Analyzing all the threat intelligence we’ve collected in the first five months of the year, Avast mobile threat researchers have been able to identify the greatest threats to Android devices in 2021. By a vast margin, the most common danger has been adware, making up 45% of the threats encountered so far this year.

Adware usually hides inside malicious apps pretending to be legitimate apps. Traditional adware can usually be found posing as gaming, photo, or other lifestyle apps. Once the app infects the device, the user is spammed with ads. Another type of adware is known as ad fraud, and it occurs in the background of an infected device, surreptitiously clicking ads on the user’s behalf without their knowledge and sometimes signing them up for premium services. 

Fake apps not holding adware comprised the second-largest threat to Android devices in 2021 so far, making up 16% of the total mobile threats. A common theme for fake apps this year has been the pandemic, and many posed as Covid-19 tracing apps. Some also posed as adblockers. Fake apps can harbor spyware or any other kind of malware, launching it the moment the app is installed on one’s device.

At 10% of Android mobile threats so far this year, banking Trojans have been the third most common. “Bankers,” as they are also known, pose as legitimate banking apps in the hopes they can fool users into entering bank login credentials. Banking Trojans hide inside malicious apps, just like adware does. 

Users who want to protect themselves against mobile malware can do the following:

• Only download apps from official apps stores like Google Play
• Check the app ratings before you download
• Carefully review permissions and app requests 
• Use a strong antivirus to block malware before it installs