What is scanning?

Question

My teacher made the comment that hackers scan. He also said that IPv4 is easy to scan and IPv6 is more difficult to scan because of the sparse use of IP addresses.

So again I say, what is scanning?

And for bonus what is the difference between a worm and a virus?

Answer 1

scanning is when you take one IP address, or several IP addresses, and, either manually or using a program like nmap, you check to see which ports are available on each of the IP addresses. Different things on your computer listen on different ports; if you have a program like ftp running on your computer, you will have port 21 open, for example. If your computer is a mail relay, then it will respond on port 25. There are thousands of ports, assigned to thousands of programs. The reason hackers care about this is because some programs on some ports are not well written, or they are often configured insecurely. Mail gateways, for example, are sometimes configured so they will allow very insecure email through. If they find that a computer is running a certain program, then the hackers can try to use well known attacks on the computer. another reason that hackers scan is because sometimes, a computer already is running a trojan or other back door program. if the computer answers on one of these special ports, the hacker knows that someone else has already messed up that computer.

that's scanning.

Answer 2

um, well, i think scanning is when a hacker tries to copy everything no matter how often the IP is used. not sure about that one sry.
Virus has become a generic term that includes all the malicious ways your computer can be attacked. Viruses are distributed by making copies of themselves or replication. Sometimes the replication itself causes damage to your hard disk. Sometimes the accumulative effect of replicating again and again disables the computer. Sometimes the energy used by replication takes over the system and there’s no computer energy left.
A Worm uses computer networks to replicate itself. It searches for servers with security holes and copies itself there. It then begins the search and replication process again.

Answer 3

Scanning (Source: wordnet.princeton.edu/perl/webwn):
-> The process of translating photographs into a digital form that can be recognized by a computer.
--> The act of systematically moving a finely focused beam of light or electrons over a surface in order to produce an image of it for analysis or transmission.

Scanning (Source: www.finr.com/glossary1.html)
--> An active, usually visual search of the environment for information. Used in reading, driving, and other daily activities.

* There are many meaning for the word scanning. If you are refering to the field of computing and IT, try and search for the word "scanning" from http://www.compuphase.com/index.html

Computer Virus is a generic term. Five types of categories of computer viruses: worm, trojan horse, macro virus, logic bomb, and time bomb.

Worms --> Use computer hosts to reproduce themselves. It travels independently over computer networks, seeking out uninfected workstations to occupy. A typical worm resides in a personal computers (PCs) memory rather than on disk.

Answer 4

Scanning is just doing a ping on a range (10.0.0.1 - 10.255.255.254 or whatever) of IP addresses to see which are active (they respond to a ping) and which are not (no response). A ping is just a computer asking "Is anyone there?" and waiting for a response. By the way, most ISP's frown on this, and can even cancel your service because of it.

Answer 5

port scanning... a port scanner searches a list of IP addresses for open ports... the open ports show intruders what services your computer has available here is a list of port assignments http://www.iss.net/security_center/advice/Exploits/Ports/
for a port scanner http://www.snapfiles.com/get/superscan.html

Answer 6

Your avatar has the cutest smile...I bet they know the answer to your question.