One in five companies in Germany says it is feeling the effects of hybrid threats from abroad, including cyberattacks, disinformation, espionage and sabotage, according to a survey by the German Economic Institute (IW).
The institute surveyed 1,041 companies and found that larger firms with more than 250 employees were particularly affected.
Companies said the threats had prompted them to improve security at their sites or had disrupted their day-to-day operations.
By sector, information and communications companies perceived the greatest risks, followed by firms involved in energy and water supplies and waste management.
Hybrid attacks can involve a combination of military, economic, intelligence and propaganda measures. They also include cyberattacks and disinformation campaigns aimed, for example, at influencing public opinion ahead of elections.
Siemens Energy chief executive Christian Bruch earlier this week told dpa that the threat level had risen significantly over the past 12 to 18 months.
He called for a civilian emergency plan to help respond to crises and protect electricity and water infrastructure as well as food supplies.
The IW said its findings showed that Germany needed to become better prepared to defend itself against such threats.
While many companies had increased investment in IT security and digital infrastructure, only a small proportion had better secured their energy supplies or drawn up emergency plans for failures of critical infrastructure.
"The lack of preparedness has a destabilizing effect on the functioning of the economy and society," the IW warned.