Cryptolocker, a highly malignant form of malware that first appeared in September 2013, is a game-changer. After signing in to your computer, it will encrypt all your data files from your word documents to photos, videos and PDFs. It then asks for a ransom of about US $ 300, or 0.5 Bitcoins to get them back. It has become one of the most commented developments in computer security circles in recent times, and imitators appeared.

Criminals have tried to make this kind of work cryptoviruses effective for decades, but only now have they got it right. You can take some simple steps to protect yourself, but this threat will grow globally for some time.

Far from being a surprise, the arrival cryptolocker easy to predict. I’ve taught cryptoviruses for more than 10 years in my lectures, and others have been aware of the threat for almost 20 years. But cryptolocker is the first example of engineering work on a large scale and for a sustained period.

Of the brain light to your desktop
Credit where credit is due: cryptolocker is the work of one or more criminals, who may nets tens or hundreds of million ransom, but the original concept was fully developed in the mid 1990s by Moti Yung, a researcher cryptography at Columbia University who now works for Google and PhD student at the time, Adam Young.

Fortunately, criminals are not known for their love of academic papers that cryptovirus proposed by Yung and Young went largely unknown outside the academic community for nearly 20 years.

In some ways it is a good thing. We avoid falling victim to this scam for a while. But on the other hand, if we had paid more attention to these two brilliant researchers in the first place, we might have been better placed to stop or at least limit the damage cryptolocker and similar ransomware has been done and will inevitably lead in the near future.

Until cryptolocker, other criminals have tried in vain to produce a virus that can hold files hostage until the money changed hands. They are mostly isolated efforts by individuals and most fall destroyed because the people behind them only have a passing knowledge of cryptography.

Most is an epic fail and hardly even be called cryptoviruses. The AIDS trojan, CryZip, Skowor and Arhiveus an example of an attempt to generate viruses that can hijack computer files but all achieve success is limited because the brain behind them did not quite make the grade. More technically, they do not use public key encryption so that they are all easy to reverse in order to extract the key without paying. Read more..

The first real threat is the family PGPCoder / Gpcode of cryptoviruses. The author behind this malware is updated every time the antivirus company announced a breakthrough, using trial and error to stay ahead of the game.

The authors cryptolocker, on the other hand, seems to have got the right recipe the first time. That would suggest they are well-educated people who are experienced in cryptography. But even this was a smart cookie not appear to have read the letters produced by the Columbia researchers because they have yet to implement virus in a way that exactly Yung and Young suggested.

Cryptolocker main window, with its countdown timer. Realfintogive / Wikimedia Commons
A recent survey of over 1,500 UK computer users show that 3.4% said they had been exposed to the virus cryptolocker, shows that more people than expected could have casualties. Of those who have been affected, a surprising 41% claim to have paid a ransom.

If these numbers play out in the general population in the UK, we see a multi-million pound operation – one of the most successful of its kind.

Bitcoin has played an important role in the success cryptolocker, which might partially explain why it has grown to where others have failed. Before bitcoin, it is easier to investigate online payment