Of those 25 million devices, India has been hit the hardest, taking the brunt of the attacks with 15 million infected devices. Agent Smith, which was first observed in the wild by Check Point Research earlier this year, has been coursing through the Google Play Store.
After monitoring the its attack vector, Check Point Research was able to summarize Agent Smith's modus operandi into three parts. First, the malware lurks in apps on Google Play, most usually disguised as photo apps, games or adult-themed apps. Users voluntarily download these apps, but they are for the most part non-functioning, which should be the first tip-off that something is amiss.
Secondly, the so-called "dropper app" will decrypt and install a malware APK automatically, which is disguised as the Google Updater. Finally, the malware will peruse a copy of the device's currently installed apps and replace target apps with versions that are infected with malicious ads. All of this is done seamlessly in the background, but users are then bombarded with newly tainted apps that are overrun with ads that of course generate revenue for their perpetrators.
With nefarious individuals become even more crafty in their attempts to infiltrate mobile devices in an effort to make money, Check Point Research is advising users to become even more vigilant. “Combining advanced threat prevention and threat intelligence while adopting a ‘hygiene first’ approach to safeguard digital assets is the best protection against invasive mobile malware attacks like 'Agent Smith', the research firm notes.
"In addition, users should only be downloading apps from trusted app stores to mitigate the risk of infection as third-party app stores often lack the security measures required to block adware loaded apps.”
Google has worked with Check Point Research to remove offending apps from the Play Store, and while Asia was the primary target, there has been a sizable number of victims found in the United States and the United Kingdom.