DoS attacks and bitcoin

Question

I was wondering what the repercussions were if a Bitcoin exchange or website that holds bitcoins were to succumb to a DoS attack.

In my understanding, all a denial-of-service attack does is deny legitimate users access to the website. However, btc-e.com, a large Bitcoin exchange, and many Tor hidden services (which use Bitcoin as a primary form of payment) seem to fall victim to DoS attacks.

Does this leave these websites vulnerable to bitcoin theft? If not, why perform the attack in the first place?

Thank you all.

Answer 1

DoS attacks do what you said: they prevent users from accessing the service. DoS by itself does not mean that theft is possible, although sometimes DoS attacks happen in order to distract those running the service from noticing another type of attack or to trigger known remediation processes that the attackers can exploit in order to perform a different attack.

In the case where theft is not the end goal, why DoS? Why do some people pull the wings off flies? Some people just like to watch the world burn.

Answer 2

A DoS attack consist of a large amount of 'requests' to the server/service. In the end, the server becomes unreachable for legitimate users. Imagine 2500 people forcing themselves into a city bus, 'normal' travelers will be unable to get on the bus due to the immense amount of traffic.

But, to answer your question; A DoS attack has very little to do with the vulnerability of a certain webserver/service. As @schroeder states, it can indeed be used as a decoy for a real hack-attempt.

How vulnerable BitCoin is to theft is a complicated issue, it's more likely that an individual user will be tricked/fooled in order to steal BitCoins. But there is, of course, always a change that a major service will be breached. These hackers are willing to work on major hacks for several months in order to find the exact method of penetration..