Q & A on global cyber attack


A massive hack crippled computers across the world on Friday in what was described by experts as a cyber attack unprecedented in scale.


Q: What happened?

A: Tens of thousands of computers in homes, businesses and government agencies were infiltrated by malicious software that encrypted and blocked access to content until users paid between $US300 ($A406) and $US600 ($A812) in the digital currency bitcoin. Nearly 100 countries were hit in the attack.

Q: What accounts for its scale?

A: Hackers exploited vulnerabilities in the most widely used operating system in the world: Microsoft Windows. The software giant issued a fix in March to correct the security flaw, but computers that did not run the update were susceptible to infection.

The highest-profile organisation to fall victim to the cybercrime was Britain’s National Health Service, which uses the 15-year-old Windows XP operating system on its computers.

Windows XP is so old that Microsoft was no longer offering free software updates for it. The company announced on Saturday that it was reversing that policy.

Q: How does the malware enter the computer?

A: The cyber weapon involved in the attack is malware known as Wanna Decryptor or WannCry. It infiltrates computers by way of links and attachments in spam emails.

Security experts say unknown hackers took advantage of tools stolen from the US National Security Agency. Portions of the spy agency’s sophisticated cyber arsenal have been leaked online in recent months.