New research suggests that an elaborate cybercrime ring is responsible for stealing between $3 million and $5 million worth of revenue from online publishers and video advertising networks each day. Experts say the scam relies on a vast network of cloaked Internet addresses, rented data centers, phony Web sites and fake users made to look like real people watching short ad segments online.

A decade ago, if a desktop computer got infected with malware the chief symptom probably was an intrusive browser toolbar of some kind. Five years ago you were more likely to get whacked by a banking trojan that stole all your passwords and credit card numbers.

A security researcher has discovered a critical vulnerability in Facebook Messenger that could allow an attacker to read all your private conversation, affecting the privacy of around 1 Billion Messenger users.

The latest incident to emerge – which happened in 2013 – is probably distinct from the breach of 500m user accounts in 2014.