It has been indicated that 2009's most malicious cyberattack is the 7/7 DDoS cyber attack. In the 7/7 DDoS cyber attack, unknown hackers were able to mass produce zombie PCs without the knowledge of their owners, and trigger certain attack mechanisms such as Mydoom which affected certain website's downloads and networks. Even virus checking programs weren't able to completely mitigate this cyberattack's capabilities. Also, virus checking companies were struggling to fully halt this attack.
Kim Jang Joong, President of ESTsoft, stated, "This last 7/7 DDoS attack created a great disturbance. The zombie PCs created mass amounts of malicious attacks. The special trait of this attack was that someone was able to delicately mass produce and realize its grand shape."
He also stated, "The 7/7 DDoS attack also affected the country's webhard website which allows its users to upload files and share them with others. This attack made the PCs of unaware computer users into zombies which unknowingly aided in this malicious cyberattack."
This past August's Win32/induc virus ranked as the 2nd most destructive and malicious cyberattack of the year.