Logic bombs: A logic bomb is a program code, usually running as agenda. For example, a worker of any company decided to put a program like this, and every day at certain time or day, the program asks for a password and if this password is correct the program will continue running normally, but what happen if for any cause the worker is fired, then the program will run and ask for the password and the password will be incorrect because the other people don’t know the password, the program then will show system errors, delete files, folders.
Trojan: It is any program that is in a computer or system without being detected that’s why this name. At one point depending of how it´s programmed, the trojan will perform a specific action.
Virus: It’s a program that can reproduce itself by adding code to another program. It activates while the program containing the virus runs. Viruses also will perform a specific action depending on how it’s programmed.
Worms: This type of program automatically (unlike a virus) duplicates itself many times.
There are another terms like zombies, spywares, botnets, etc.
What is a zombie? A zombie is a program that acts sending packages, information or performing another activity defined by its programmer. It can act in different computers, not just in one, therefore, we could have a computers army realizing a specific action.
A botnet is mainly used to make DoS attacks (Denial of Service). This type of attacks are used to broke servers. They can use their computer as a proxy and all the information seen will be sended to the programmer.
At the moment a server receives a request for something, it responds.
DoS (Denial of Service)
A denial of service usually works making a lot of requests to a server, saturating its bandwidth. Now users won’t have access to it, making the server unable to answer requests.
How can we accomplish that? Sending packages to the server or the user we are going to attack. What we used to do was to send a large amount of packages, saturating its bandwidth, but now there are some protocols that won’t let us do it, therefore what we now do is to infect some computers, so that they can be sending packages or making a lot of requests.
For example, if we have a brother or a friend that is all day watching videos in youtube, downloading music, using out network and making it slower, what we can do is to send them some pings. Now he’ll start to see its internet slower because we are saturating its bandwidth. We must know that by doing that, we are also affecting out bandwidth so it is recommended to use more computers when we are making this kind of attacks.