The FBI and the Federal Trade Commission have issued a warning against 'Cryptolocker', a malicious software that bars access to computer files, including personal documents and photos, until users pay a "ransom" of about USD 300 (over Rs 18,600).
"Cryptolocker, a malware programme holds the files on your computer for ransom, and doesn't allow you to access them until you pay up. Even then, there's no guarantee. It's essentially extortion, with all your personal documents, photos, and files at risk," the federal agencies said in an advisory.
Cryptolocker, which has been in the news since last year, spreads mostly through email and 'drive-by' downloads.
In November last year, the UK government had also issued a similar warning. According to a report by Dell Secureworks, Cryptolocker ransomware had infected about 2.50 lakh PCs globally by mid-December 2013, with the US and the UK being the worst affected.
The email might look like a routine message from a legitimate company, like a tracking notice from a shipping company.
"If you click on the hyperlink in the email, Cryptolocker encrypts everything on your hard drive and in your shared folders," the advisory issued yesterday said.
When the job is done, the user gets a 'ransom note' demanding payment of about USD 300 (over Rs 18,600) via Bitcoin or some other anonymous payment method, it added.
"The criminals behind this malware say they'll give you the encryption key if you pay, but they're hardly trustworthy. And there's no other way to unlock your files," the advisory said.
According to security experts, the best way to minimise risks of such damage is to often back up computer files.
