Hackers are exploiting a serious flaw in the internet's architecture, according to a security firm. The bug apparently targets systems which convert URLs into IP addresses. Exploiting it could threaten the smooth running of internet services as it allows hackers to launch denial-of-service attacks on websites, potentially forcing them offline. Bind is the name of a variety of Domain Name System (DNS) software used on the majority of internet servers. The recently identified bug allows attackers to crash the software, therefore taking the DNS service offline and preventing URLs, for example, from working. A patch for the flaw is already available, but many systems are yet to be updated.