What is Malware?
Malware (short for malicious software) is harmful software designed to damage, disrupt or gain unauthorised use of systems, networks or data.
Malware is one of the greatest digital threats to both IT and OT environments and exists in many forms and variants.
🧬 Types of malware
| Type | Description |
|---|---|
| Ransomware | Encrypts files and demands a ransom for recovery |
| Spyware | Covertly collects information (such as passwords or keystrokes) |
| Trojan Horse | Poses as legitimate software while opening a backdoor |
| Worm | Spreads automatically across networks without human interaction |
| Virus | Attaches itself to files and spreads by infecting other programs |
| Rootkit | Hides processes or access, often to maintain persistence |
| Adware | Displays unwanted advertisements and may track user behaviour |
| Botnet agent | Makes systems part of a network that can be controlled remotely |
🧠 How does malware get in?
- Via Phishing emails or fake websites
- In infected attachments or USB sticks
- Through software vulnerabilities (CVE)
- Via remote access without an adequate Firewall or VPN
- Through compromised updates or third-party suppliers (supply chain risk)
💥 Risks of malware
- Data breaches or loss of intellectual property
- Encrypted or deleted files
- Production downtime in OT environments
- Reputational damage or loss of trust
- Compliance issues (e.g. notification obligations under NIS2 or GDPR)
✅ Protection against malware
- Use of EDR, Antivirus, SIEM and Zero Trust
- Regular updates and patch management
- Network segmentation (DMZ, VLAN, Air gap)
- Awareness training against Social Engineering
- Immutable Backup and Disaster Recovery planning
📌 In summary
Malware is malicious software that harms your systems or data, often as part of a wider cyber attack. Protection requires a combination of technical measures, policy and awareness.