30 Days of Security Testing – Day Twenty

The challenge for Day Twenty is – Read about DOS/DDOS attacks. Share examples/stories via social media.

A DOS attack or Denial of Service Attack is where the attacker seeks to make a resource or machine unavailable to it’s intended audience or user.  This is usually done by spamming the target with too many requests for it to handle.


One metaphor for a DOS attack that I like is a knock-knock joke.

In a knock-knock joke, the recipient of the joke gets to the punchline by answering a prompt and returning an expected response.

“Knock Knock” followed by “who’s there?” leads to the next part of the joke.

But imagine if when you say “who’s there?” instead of progressing to the next part of the joke, the joke teller instead responds by repeating “knock knock” until you give up – or they say “knock knock” so often and so quickly that you don’t get an opportunity to say “who’s there?”

In this scenario you as the recipient of the punchline have been denied a service.

A DDOS or Distributed Denial of Service attack is a DOS attack that originates from a huge number of individual (“distributed”) sources.

Probably the biggest and most well known DDOS attack to date (as of Dec 18) was against GitHub back in Feb this year.

From GitHub’s own release they describe the attack as “The attack originated from over a thousand different autonomous systems (ASNs) across tens of thousands of unique endpoints. It was an amplification attack using the memcached-based approach described above that peaked at 1.35Tbps via 126.9 million packets per second.”

Amazingly however GitHub was only unavailable for around 10 minutes before being able to restore service.

Digital Attack Map shows a pretty cool visual representation of DDOS attacks around the world.



Thanks for reading my post and following my progress through the 30 Days of Security Testing.

For more on Security Testing please visit here  or any of my other ramblings visit here

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