Abstract: In today’s high technology world, Organizations are becoming more and more dependent on Internet Technology and Information System. There are millions of users are using Internet and dependent on Information System. Sensitive and Confidential information is shared through internet and it must be protected. The threat to the information security from criminals like Hackers and terrorist are increasing. Threats are widely increasing as internet grows. Different kinds of attacks are used to harm the system and to get confidential information. Attacks like Distributed Denial of Service, SQL injection, Brute force, Cross site Scripting are used to break down the Sensitive systems and make them vulnerable.
Keywords: SQL Injection, DDoS (Distributed Denial of Service), brute force attack, Threshold Value.