polimd/Computer Security/lesson_18.md

Computer Security - lesson 18

Stefano Zanero

17 June 2016

Viruses

Look for ted talk history and viruses.

From 2004 on the production of worms stopped because the people that were developing worms put themselves in business and began creating ransomware, scareware and state-sponsored malware.

Ransomware is a form of getting money from malware.

Most computer viruses are not harmful because a virus that takes down the host as soon as it's infected, cannon propagate. For example cold infection is a lot more effective than ebola because it does not kill you and let you propagate it.

Before the introduction of macro viruses, people were trained on the fact that office documents were harmless and could be opened safely, but after introduction of macro language in office, macro viruses began to spread.

TCP connection are latency bound, so the more is loaded one of the host, the slower the connection will be. So TCP based viruses like code-red were slowing down themselves. But UDP based viruses like SQL hammer are much more effective.

SQL hammer was based on the assumption that there were databases exposed on the internet while they didn't have any reason to be.