When a bank, government office or online store site suddenly goes down, the instinct is to think someone broke in. But often nobody got in anywhere; the site was simply flooded. That is a DDoS (distributed denial-of-service) attack, one of the oldest and most common forms of cyberattack, and in recent years one of the fastest growing.
The idea is simple. Any site can handle only so many requests at once, like a supermarket checkout that can serve a limited number of customers. In a DDoS attack, the attacker sends so many requests from huge numbers of computers at once that the site cannot cope, and real customers cannot get in. Those computers are usually a 'botnet': thousands, sometimes millions, of devices hijacked without their owners' knowledge, such as security cameras, routers and home computers, operated together remotely.
There are several types. Some target the network itself, trying to choke the 'pipe' connecting the site to the internet with huge volumes of data. Others target the application layer, imitating real users requesting pages or running searches, which makes them harder to spot. According to Akamai reports, DDoS attacks on the financial sector now last much longer than before, and application-layer attacks doubled within two years, partly thanks to AI tools and botnets for hire.
Who is behind them? Sometimes hacktivist groups wanting to protest and embarrass an institution or country; Israel, for example, is regularly hit by politically motivated attacks. Sometimes criminals demanding a ransom to stop, sometimes competitors or state actors. Today you can 'rent' a DDoS attack online cheaply, making it accessible to almost anyone.
How to defend? Most organizations do not handle this alone but use protection services from companies such as Akamai, Cloudflare and others, which filter traffic and pass only real requests to the site. But as companies like Israel's MazeBolt warn, having protection does not guarantee it is configured correctly, so it should be tested regularly. And private users have a small but important role: update and change default passwords on cameras and routers so their devices do not become part of a botnet.
