Detection and blocking of spammers using SPOT detection algorithm

Spammers are one of the key security related threat on the Internet nowadays. Attackers can recruit a large number of machines at economic intensive through spamming. Spam zombies are compromised machines in a network which are involved in the spamming activities. Spammers use spam zombies to perform cyber crimes. Spamming causes wastage of network bandwidth. So it is a significant challenge for system administrators to identify and block the spammers in a network. The existing spam zombie detections algorithms are PT(Percentage Threshold), CT(Count Threshold) and SPOT. This paper shows comparison of these spam zombie detection algorithms. The result shows that SPOT gives good result as compared to PT and CT. The proposed system assists system administrators to automatically detect the spammers in their networks in an online manner. For spammer detection the system uses a SPOT detection algorithm which is based on a statistical tool known as Sequential Probability Ratio Test (SPRT). The experimental results shows that the SPOT detection algorithm detects the spammers very effectively. The system blocks the spammers and user can reactivate their account by passing a security test. The system also detects and deletes emails with virus files in the attachments. The proposed system focuses only on detection of spammers and not the prevention.