Massachusetts cops have admitted paying a ransom to get their data back on an official police computer infected with the devilish Cryptolocker ransomware.

Cryptolocker is a rather unpleasant strain of malware, first spotted in August, that encrypts documents on the infiltrated Windows PC and will throw away the decryption key unless a ransom is paid before a time limit. The sophisticated software, which uses virtually unbreakable 256-bit AES and 2048-bit RSA encryption, even offers a payment plan for victims who have trouble forking out the two Bitcoins (right now $1,200) required to recover the obfuscated data.

On November 6, a police computer in the town of Swansea, Massachusetts, was infected by the malware, and the cops called in the FBI to investigate. However, in order to get access to the system the baffled coppers decided that it would be easier to pay the ransom of 2 BTC, then worth around $750, and received the private key to unlock the computer's data on November 10.

"It was an education for [those who] had to deal with it," Swansea police lieutenant Gregory Ryan told the Herald News. "The virus is so complicated and successful that you have to buy these Bitcoins, which we had never heard of."

Ryan said that essential police systems weren't affected by the infection, and federal agents are still investigating the infection, hopefully to find clues that'll lead the Feds to the malware's writer. The software nasty is thought to have been the work of Eastern European criminal gangs, but no one knows for sure.

"The virus is not here anymore," Ryan said. "We've upgraded our antivirus software. We're going to try to tighten the belt, and have experts come in, but as all computer experts say, there is no foolproof way to lock your system down."

Apart from not being a fool that is. Cryptolocker primarily spreads via email attachments, typically a PDF that claims to be from a government department or delivery service. As ever, experts advise not to open attachments unless you are sure of its contents and the source. ®