It is thought as many as 25 million Android phones have been infected with Malware dubbed Agent Smith. The malware replaces installed apps like What’s App with evil versions that bombard users with adverts.

Most of the infected phones have been in India, however a surprising number have been in the US and UK. The malware has spread via a third party app store 9apps.com, which is owner by China’s Alibaba.

Read More: Forbes