Hacking for espionage purposes is sharply increasing, with groups or national governments from Eastern Europe playing a growing role, according to one of the most comprehensive annual studies of computer intrusions.

Spying intrusions traced back to any country in 2013 were blamed on residents of China and other East Asian nations 49 percent of the time, but Eastern European countries, especially Russian-speaking nations, were the suspected launching site for 21 percent of breaches, Verizon Communications Inc. said in its annual Data Breach Investigations Report.