The digital environment of cyber society is being affected by intruders, cybercriminals, and neighboring countries. The ongoing research in the field of cybersecurity is therefore playing an important role and a huge impact on society. The main objective of this research is to measure the level of security and analyze the behavior of cyber-attack via Information and communications technology (ICT) tools. The idea is to improve security by highlighting the behavior of attacks (i.e., gaps, weak points, and solutions) to control the crimes. We have conducted the distributed-denial-of-service (DDoS) attack using Wireshark and LOIC. For the DDoS attack, TCP flooding is chosen to analyze the behavior of organizations in three aspects (i) before attack, (ii) during attack, and (iii) after attack. Two organizations of Pakistan have been chosen to analyze their behavior. The simulation results in terms of the number of packets and average packet per second indicate the cyber security level of organizations against DDoS attacks. In addition, the accumulated results (i.e., before, during, and after the attack) could be used for the analysis of large-scale DDoS.