UK warns of ransom scam targeting 10s of millions

The British government has issued an unusually stark warning about a cyberscam that locks users out of their computers unless they pay a ransom, saying that tens of millions of people may soon be targeted.

In a message headlined "URGENT ALERT," Britain's National Crime Agency said today they were aware of a "mass email spamming event that is ongoing" and urged computer users to beware messages purporting to come from their bank.

The scam works by tricking users into downloading CryptoLocker, a piece of malicious software that encrypts a user's hard drive, effectively scrambling all their personal documents and photos.
 

A countdown clock appears on the screen warning that the files will be lost irrevocably unless a ransom is paid, typically through hard-to-trace cybercurrencies such as Bitcoin.