New report: Could a cyberattack paralyse Denmark?
A report by the IT University of Copenhagen, the University of Southern Denmark, and the Danish Institute of Fire and Security shows that successful cyberattacks on the telecommunications sector have had major consequences in Ukraine and offers a number of recommendations for how Denmark can strengthen both defence and emergency preparedness.
Written 11 May, 2026 15:31 by Jari Kickbusch
Based on data from Denmark and Ukraine, researchers from the IT University (ITU), the University of Southern Denmark (SDU), and the Danish Institute of Fire and Security (DBI) have investigated to what extent Danish society is vulnerable to attacks on the telecommunications sector. The results highlight several challenges. Even though both the government and telecom companies are investing heavily in defence and preparedness, there is considerable uncertainty about whether we are ready to handle and withstand an intensified cyberwar or hybrid war. This is the key message in the report, Optimising Denmark’s Cyber Emergency Preparedness, which is the result of a research project funded by the National Defence Technology Centre (NFC).
The report is based on qualitative interviews with Danish and Ukrainian authorities as well as employees in the telecommunications, healthcare, and transport sectors. In addition, the researchers interviewed Ukrainian civilians about the economic, societal, and personal consequences of the numerous attacks on digital infrastructure.
Cyberwar costs lives
The interviews with Ukrainian civilians first and foremost underscore the seriousness of the cyber threat. Just as in Denmark, most Ukrainians are deeply dependent on telecommunications in order to buy food, use public transport,or contact their doctor. A GP interviewed for the study reports that the interruptions to phone and internet connections have had fatal consequences:
“So one of my patients, suddenly he didn’t have an internet connection and no mobile phone connection. What to do? He was in pain, took ibuprofen. Paracetamol. That’s all. Then he began to vomit and feel nausea. And then when he came to me 5 or 10 days later, he had a big myocardial infarction and could only be saved by a heart transplantation. He lost precious time, the gold time for cure,” he says.
The Principal Investigator of the project, Associate Professor at the IT University, Oksana Kulyk, explains that the interviews from Ukraine show how difficult it can be to predict the consequences attacks on digital infrastructure may have for the civilian population:
“Depending on the scope of the outage, people might be unable to get support or accurate information from the government, connect to emergency services in case they need help, or get in touch with their family to check on their well-being. Unless Danish society can prepare for such outages, the consequences can be drastic,” says Oksana Kulyk.
The threat to Denmark
Several of the interviewees from Denmark’s critical sectors were highly concerned about the cyber and hybrid threat. One of them says:
“The threat is constantly lurking out there. It is no longer a question of whether we will be hit by an attack. It’s a question of when we’ll get attacked. That is also why the threat level against Denmark has never been higher. We are pushed to the forefront now.”
In the report, the interviewees identify a number of serious threats to Denmark’s critical infrastructure, including:
- DDoS attacks, where servers, networks, or websites are overloaded with enormous amounts of data.
- Social engineering, for example through phishing emails.
- Ransomware attacks, where malicious software (malware) encrypts files or locks computers.
- Supply chain attacks, where attackers exploit suppliers and supply chains.
- Insider attacks, where an employee either carries out an attack themselves or helps others to do so.
- Hybrid attacks, where cyber and physical attacks are combined.
How prepared are we really?
Several participants were also concerned about how well prepared we are for successful attacks on critical infrastructure, for example if phone and internet connections disappear from one moment to the next. In the guidelines, Be Prepared for Crises, the Danish Emergency Management Agency and the Agency for Civil Protection (SAMSIK) underscore that telecommunications is an important part of preparedness while recognising that access to digital communication may be disrupted during a crisis.
The recognition of both the importance and vulnerability of telecommunications leaves us with an open question: How well is civil society in Denmark actually prepared for telecommunications outages? While the authorities and companies responsible for our critical infrastructure may have separate communication lines to be used during a crisis, several interviewees point out that civilians’ communication needs are overlooked:
“I am worried that the first thing an enemy would do is to attack our communication channels either physically or virtually. And I don’t want to think about a scenario where people cannot use their mobile phones and all kinds of other communication devices. It will be a state of panic. Just remember when Mette Frederiksen said there was no need to stock toilet paper. Everybody went out to buy toilet paper.”
Recommendations
One of the central messages of the report is that better cybersecurity and preparedness cannot be achieved with technical solutions alone. Effective defence and emergency preparedness also require clear emergency plans, exercises, cross-sector cooperation, and not least a focus on human behaviour. The report recommendations include:
- Stronger collaboration across sectors because the telecommunications sector is highly dependent on the energy sector.
- Better guidelines for the population.
- Increased redundancy and exploration of alternative telecommunications solutions.
- Stronger collaboration between authorities and the telecommunications sector, for example regarding the protection of submarine cables.
- More exercises to test preparedness in crisis situations.
The researcher behind the report hopes that it will contribute to a better understanding of why attacks on digital critical infrastructure often have consequences far beyond the authority or company that is targeted.In Ukraine, there are many examples of chain reactions where people cannot buy food, refuel their cars, or find out whether their family or friends are safe.
“Protection against and mitigation of these attacks requires a systematic approach, involving public and private sector stakeholders as well as international collaboration,” says Associate Professor at Syddansk Universitet, Peter Mayer. Oksana Kulyk adds:
“Such an approach requires consideration of many factors, addressing both technical challenges as well as human and societal aspects of cyber resilience.”
Learn more about the project on DBI’s webpage
Jari Kickbusch, phone 7218 5304, email jark@itu.dk