This past week has been devastating on the online frontiers as computers worldwide have been hit by the WannaCry ransomware. The malware is capable of locking down your system until you pay a ransom, and is also leveraging on a vulnerability found in Windows.
22-year-old British cybersecurity researcher Marcus Hutchins was studying the code and saw a set of instructions that directed it to check the URL. Just to know why that was happening, he registered the URL name in the code and simply $10. This helped security researchers buy some time because this stopped the malware's ability to spread to other systems.
So @Hacker0x01 have awarded me a $10,000 bounty for the "kill-switch". I plan on splitting it between to-be-decided charities and education.
— MalwareTech (@MalwareTechBlog) May 15, 2017It is said that the malware had a kill switch that was hidden in this bogus URL. WannaCry kept checking the URL each time it infected a computer. As long as there is no live page of the URL, the malware would continue spreading and as soon as the live page existed of the bogus URL it would stop.
As soon as Hutchins registered the gibberish domain name, the attack was halted. It gave time to update security patches and so on. However, soon a new wave of attack was ready which didn't come with a kill switch.