Enlarge (credit: portal gda)
A virulent family of malware that infected more than 10 million Android devices last year has made a comeback, this time hiding inside Google Play apps that have been downloaded by as many as 12 million unsuspecting users.
HummingWhale, as the professionally developed malware has been dubbed, is a variant of HummingBad, the name given to a family of malicious apps researchers documented in July invading non-Google app markets. HummingBad attempted to override security protections by exploiting unpatched vulnerabilities that gave the malware root privileges in older versions of Android. Before Google shut it down, it installed more than 50,000 fraudulent apps each day, displayed 20 million malicious advertisements, and generated more than $300,000 per month in revenue. Of the 10 million people who downloaded HummingBad-contaminated apps, an estimated 286,000 of them were located in the US.
HummingWhale, by contrast, managed to sneak its way into about 20 Google Play apps that were downloaded from 2 million to 12 million times, according to researchers from Check Point, the security company that has been closely following the malware family for almost a year. Rather than rooting devices, the latest variant includes new virtual machine techniques that allow the malware to perform ad fraud better than ever, company researchers said in a blog post published Monday.