State-sponsored hackers from China have been developing techniques that appear to be able to bypass routine cybersecurity tools, allowing them to stealthily embed themselves in government and business networks they can then spy on for years.

This, according to Alphabet Inc.’s Google.

According to a report in Thursday’s Wall Street Journal, analysts at Google’s Mandiant division have in the past year found hacks of systems that aren’t what many might view as the most typical or ripe targets of cyber espionage.