Conficker is a malicious worm that infects computers running Microsoft Windows operating systems. It was first discovered in November 2008 and quickly spread worldwide, infecting millions of computers.
Due to its ability to evade detection, infect computers via multiple vectors, and modify system configurations, Conficker has posed a significant threat to computer security. It can steal sensitive information, such as passwords and financial data, and can also disable security software, making computers more vulnerable to other malware infections.