Traditionally, all anti-virus programs and IPS systems work using signature-based techniques. However, this doesn't help much to prevent zero-day attacks.
Therefore, what can be done to prevent zero-day attacks?
I am confused about what vnc reflector does. From the documentation http://sourceforge.net/projects/vnc-reflector/ I got that it's proxysitting between real VNC server (a host) and a number of VNC clients.
My confusion is : 1. Does it make any changes to the coming stream from server 2. Does it make 1 connection with server to connect to many client or the connections are proportionate.
Documentation is not clear in this. If anyone can help me?
Recently I read about Denial of Service attack on Amazon & PayPal. I am curious that how this is performed. These big companies must have huge servers, so DOS would require billions of bots to access it.
So my questions are
- How DDOS attack performed at this level?
- How to know beforehand that this is attack is happening?
- How to prevent this (how to distinguish from bot vs user, apart from common captcha way that is done)