Information Security

1)A)

Brute Force Attack

In a brute force attack, the intruder attempts to gain access to a server by guessing a user password (usually the root administrator) through the SSH server, Mail server, or other service running on your system. The attacker will normally use software that will check every possible combination to find the one that works. Brute force detection software will alert you when multiple failed attempts to gain access are in progress and disable access from the offending IP address.

Open Relay

A Mail Transfer Agent (MTA) normally uses an SMTP server to send email from your server’s users to people around the world. With an open relay, anyone can use your SMTP server, including spammers. Not only is it bad to give access to people who send spam, it could very well get your server placed on a DNS blacklist that some ISPs will use to block mail from your IP. It is very easy to close an open relay. Just follow the documentation for your MTA.

Botnet

Attackers use botnets to automatically run and distribute malicious software on “agent” servers. They then use the agent machines to attack or infect others. Because all of this can be done automatically without user intervention, botnets can spread very quickly and be deadly for large networks. They are commonly used in DDoS attacks and spam campaigns.

DoS

DoS stands for Denial of Service, and is a technique attackers will use to effectively shut off access to your site. They accomplish this by increasing traffic on your site so much that the victim’s server becomes unresponsive. While some DoS attacks come from single attackers, others are coordinated and are called Distributed Denial of Service (DDoS) attacks. Often times, the users of computers executing a DDoS do not even know their computers are being used as agents.

Cross-site Scripting

Cross-site scipting or XSS is a technique that makes use of vulnerabilities in web applications. According to UK dedicated hosting server specialists at 34SP.com,...