Question

Which of the following is a denial of service attack?

Group of answer choices

When a cracker enters a system through an idle modem, captures the PC attached to the modem, and then gains access to the network to which it is connected.

Both a perpetrator who sends hundreds of messages from randomly generated false addresses, overloading an Internet service provider's e-mail server AND a perpetrator who e-mails the same message to everyone on one or more LISTSERV lists are denial of service attacks.

When an e-mail message is sent through a re-mailer, who removes the message headers making the message anonymous, then resends the message to selected addresses.

When the perpetrator e-mails the same message to everyone on one or more LISTSERV lists.

When a perpetrator sends hundreds of messages from randomly generated false addresses, overloading an Internet service provider's e-mail server.

Answer 1

Denial of service attack means making either machine or a resource in network not available to the users who are using them temporarily (by disrupting services) or permanently (by crashing them).

This can be achieved by overflooding the information to the target i.e increasing the traffic which will lead to either crash the machine or network resource or causing them to slow down .

Examples of such situations are:

1. If we are sending more traffic to a network address than the system is able to handle then it will be overflown and due to heavy traffic the network might not work properly and slows down and ultimately crashes.

2. Another type isby sending a request to connect the server but never the request completes I e three way handshaking.

3. Due to DoS attacks the services will be inaccessible.

Mainly the victims of DoS attacks targets the webserver of big organizations such as in banking,commerce, government etc..

So based on the above information of DoS attacks by seeing the options provided the below option results in overflooding and makes the network to slow down and crash.

"When a perpetrator sends hundreds of messages from randomly generated false addresses, overloading an Internet service provider's e-mail server."

And

"Both a perpetrator who sends hundreds of messages from randomly generated false addresses, overloading an Internet service provider's e-mail server AND a perpetrator who e-mails the same message to everyone on one or more LISTSERV lists are denial of service attacks."

The other options are not related as due to them the network or resource is not overflooded and not accessible to the users.