Since the global spread of COVID-19, social distancing and untact service implementation have spread rapidly. With the transition to a non-face-to-face environment such as telework and remote classes, cyber security threats have increased, and a lot of cyber compromises have also occurred. In this study, cyber-attacks and response cases related to COVID-19 are summarized in four aspects: cyber fraud, cyber-attacks on companies related to COVID-19 and healthcare sector, cyber-attacks on untact services such as telework, and preparation of untact services security for post-covid 19. After the outbreak of the COVID-19 pandemic, related events such as vaccination information and payment of national disaster aid continued to be used as bait for smishing and phishing. In the aspect of cyber-attacks on companies related to COVID-19 and healthcare sector, we can see that the damage was rapidly increasing as state-supported hackers attack those companies to obtain research results related to the COVID-19, and hackers chose medical institutions as targets with an efficient ransomware attack approach by changing 'spray and pray' strategy to 'big-game hunting'. Companies using untact services such as telework are experiencing cyber breaches due to insufficient security settings, non-installation of security patches, and vulnerabilities in systems constituting untact services such as VPN. In response to these cyber incidents, as a case of cyber fraud countermeasures, security notices to preventing cyber fraud damage to the public was announced, and security guidelines and ransomware countermeasures were provided to organizations related to COVID-19 and medical institutions. In addition, for companies that use and provide untact services, security vulnerability finding and system development environment security inspection service were provided by Government funding programs. We also looked at the differences in the role of the government and the target of security notices between domestic and overseas response cases. Lastly, considering the development of untact services by industry in preparation for post-COVID-19, supply chain security, cloud security, development security, and IoT security were suggested as common security reinforcement measures.