India, April 23 -- Gmail users worldwide have been advised to stay vigilant as cleverly designed phishing scams are already slipping past the tech giant's own security systems and catching people off guard.

Artificial intelligence is helping cyber criminals make almost indistinguishable Google-sounding phone calls and follow-up emails. These emails, generally pointing out urgent legal concerns like subpoenas, are chock-full of invented urgency to make users click on malicious links.

"Cybercriminals are constantly developing new tactics, techniques, and procedures to exploit vulnerabilities and bypass security controls, and companies must be able to quickly adapt and respond to these threats," Spencer Starkey, vice-president at SonicWall...