E-mail vulnerability: what critical infrastructure operators should do now

Whether it’s healthcare, energy supply, authorities, financial systems or public transport: critical infrastructure forms the backbone of our society. In an increasingly connected world, e-mail is still the key means of communication, but is also a preferred gateway for cyberattacks.

Organizations in Germany, Austria and Switzerland in particular are increasingly being targeted and, as such, are subject to ever more stringent national and EU-wide regulations. In order to withstand digital threats, advanced measures for proof of compliance are now needed in addition to traditional protective mechanisms such as spam filters and virus protection. This requires extra resources are needed. As a result, intelligent, adaptable security solutions are more in demand than ever.

The threat situation: complex, professional, cross-border

Systemically important organizations in Germany, Austria and Switzerland are increasingly affected by attacks that specifically exploit vulnerabilities in e-mail traffic. These include:

• Targeted phishing and spear phishing campaigns based on trust and personalization
• Business e-mail compromise (BEC) attacks aimed at stealing access data or redirecting financial transactions
• Supply chain attacks via compromised third-party e-mails.

These attacks are becoming more persistent and technically savvy, and they are often part of coordinated campaigns – with significant potential for damage.

Why e-mail is so vulnerable

Many critical infrastructure organizations have invested in perimeter protection and network monitoring. Despite this, e-mail often remains the weakest link – for three main reasons:

1. Human error: even well-trained employees can be manipulated through personalized phishing e-mails.
2. Heterogeneous IT landscapes: old systems and modern cloud applications are often insufficiently integrated.
3. Cross-border communication: e-mails regularly cross national borders, making control and protection more difficult.

Rising regulatory pressure

At the same time, legislators in all three countries of the DACH region are tightening the reins:

• Germany: the German IT Security Act 2.0 requires critical infrastructure operators to implement much stricter security requirements.
• Austria: the NIS Act implements the European NIS Directive nationally and requires high standards for reporting obligations and protection measures.
• Switzerland: the National Cyberstrategy (NCS) creates clear requirements for critical infrastructure sectors – even though Switzerland is not an EU member.

One thing is clear: requirements are growing – alongside the increase in digital communication.

Modern e-mail security – what matters now

A holistic approach is required to meet the needs of the threat situation and regulatory requirements:

• AI-based threat analysis that adapts to new attack patterns in real time
• Behaviour-based anomaly detection to identify suspicious activities early
• End-to-end encryption for maximum confidentiality
• Automated response mechanisms to take rapid and targeted action in emergencies.

A strategic imperative – not a technical side issue

E-mail security has long gone beyond spam filters and virus protection – it’s all about protecting operational integrity, public security and national resilience.

To sum up: strong e-mail security is mandatory for critical infrastructure organizations in the DACH region. In light of complex threats and strict regulations, intelligent defence systems are essential. E-mail is still the main gateway for attacks – so let’s secure it.