WannaCry malware exploited OS weakness to spread

The recent ransomware cyberattack has claimed an estimated 300,000 computers in 150 countries.

Cyber security expert Justin Cappos is a professor at NYU's Tandon School of Engineering. He described what the WannaCry malware is doing now and how it invades computers through a loophole in Microsoft Corp's Windows operating system. He said the malware exploits a weakness in the operating system to spread from computer to computer.  Microsoft issued a patch in March that closed the loophole but people who didn't update or are using pirated versions of Windows were vulnerable.

Most worms activate when you click on a link or download a file. WannaCry activates on its own. Then it takes over the computer and encrypts all of the files. You can't access anything. Then users are told to provide payment, in this case in Bitcoin, and hope the hacker answers.

On Friday, 70 countries were immediately hit. Now computers in an estimated 150 countries have been infected. The NSA created the worm, according to reports, and it somehow leaked. The U.S. government has not denied that information.

Experts said that ransomware is here to stay. So take these simple steps: keep offline backups of really important files and enable automatic updates of your operating system and other software.

British computer expert Marcus Hutchis, who is credited with cracking the WannaCry cyberattack, told the AP that he is not a hero and that fighting malware is "the right thing to do."