A massive cyber war exercise, Cyber Europe 2012, is being held across Europe today.

"ENISA (European Network and Information Security Agency), which is co-ordinating the event, said 25 nations were actively participating in the practice run, and a further four countries were observing," BBC News reports.

"It's the second exercise of its type, following the running of a similar pan-European simulated DDoS attack scenario two years ago," writes The Register's John Leyden. "'Compared to the 2010 exercise, Cyber Europe 2012 has grown considerably in scope, scale and complexity,' according to a statement by ENISA."

"This is first Cyber Europe event to include participants from the private sector -- specifically the finance sector, ISPs and eGovernment -- not just the public sector," writes TechCrunch's Natasha Lomas.

"In Cyber Europe 2012, 400 experts from major financial institutions, telecoms companies, internet service providers and local and national governments across Europe are facing more than 1,200 separate cyber incidents (including more than 30,000 emails) during a simulated DDoS campaign," Help Net Security reports. "The exercise is testing how they would respond and co-operate in the event of sustained attacks against the public websites and computer systems of major European banks."

"The event is among a growing number of simulated attacks aimed at driving cross-border cooperation among organizations in the digital domain," writes Nextgov's Dawn Lim. "The United Nations’ International Telecommunication Union and the cybersecurity coalition International Multilateral Partnership Against Cyber Threats held a drill in December with teams from Cambodia, Laos, Myanmar and Vietnam. The Indian Computer Emergency Response Team kicked off a two-day joint offensive exercise with the United States in September."