A DoS attack is where cyberattackers seek to make a machine or network inaccessible to its intended users. DoS attacks can be executed by either flooding networks with traffic or by sending information that triggers a system slowdown or complete crash. As with DDoS attacks, DoS attacks tend to focus on high profile organizations or ones with popular, public-facing websites such as banking, ecommerce, media or government institutions. DoS attacks deprive legitimate users of the service they want to access, and cause extensive damage to the victim, due to security and cleanup costs, loss of reputation, loss of revenue and customer attrition.
Defending against a Denial of Service attack can be quite straight forward but there are a number of aspects of defense that must be considered.
- The majority of Denial of Service attacks are caused by exposed vulnerabilities in systems. Ensure your systems are patched and up to date, ideally within 14 days of patch release as advised by the NCSC in their Cyber Essentials Standard.
- Perform vulnerability scans every month and FIX the issues identified.
- Configure your firewalls to prevent your network from being flooded with traffic.