Cyberattack against major companies appears to be 'vandalism,' says ex-FBI agent

The global cyberattack that hit companies and government officials on Tuesday appears to be "cyber vandalism," former FBI agent Leo Taddeo told CNBC.

"It's hard to understand from that point of view who would go through the time and effort to create this kind of impact," Taddeo said Tuesday on "Squawk Alley." Taddeo is chief security officer at data center firm Cyxtera, and former special agent in charge of the Cyber and Special Operations Division for the FBI's New York Office.

"It could be a nation-state that is trying to get our attention," added Taddeo, who spoke after a major cyberattack caused widespread disruption across Europe on Tuesday.

Companies reporting disruptions include Russia's Rosneft oil company, Danish shipping giant A.P. Moller-Maersk, U.K. ad giant WPP, and U.S. drugmaker Merck.

The latest attack came after a previous outbreak of ransomware WannaCry, which spread rapidly using digital break-in tools originally created by the U.S. National Security Agency.

"When you try to find the motive, it's hard to understand," Taddeo said.

— The Associated Press contributed to this report.