Switzerland is being targeted by hackers distributing malicious software or pursuing politically motivated goals.
The Reporting and Analysis Centre for Information Assurance (Melani) can now block .ch domains if they are being misused.
Between June and August 2010, Melani identified 145 cases of misuse in more than 237,000 websites checked.
With the number of cases of espionage and stolen data rising worldwide in the first half of 2010, espionage is more common than ever.
On Tuesday, a government statement said data was often obtained illegally for financial or criminal interest, but also as part of espionage condoned by foreign governments.
swissinfo.ch and agencies