Symantec has released a white paper that focuses on this threat

Nov 9, 2012 10:23 GMT  ·  By

Security firm Symantec has released a white paper which details ransomware, the type of threat that locks up infected computers and asks their owners to pay a ransom if they want to see the devices set free.

According to the paper – called “Ransomware: A Growing Menace” –, over the past year, ransomware infections have been spotted in many locations, from Eastern to Western Europe, Canada and the United States.

Initially, ransomware encrypted files and asked victims to pay for the decryption key. Then, in 2009, cybercriminals started targeting Russian speakers with malware designed to lock their computer screens in the name of the local law enforcement agency and, more recently, even in the name of Anonymous.

The payment requested by the crooks varies depending on the country. Some ask for $200, while others for 100 EUR.

These amounts must be paid in 72 hours or less via untraceable electronic payment systems.

The figures show that, on average, 2.9% of users whose machines are infected fall for the trap and pay up.

For instance, a smaller criminal group that infected around 68,000 machines in one month could have earned as much as $400,000 (312,000 EUR).

On the other hand, a larger ring that relied on the Reveton malware to infect 500,000 in just 18 days could have made much more money.

It’s believed that in one year a total of over $5 million (3.9 million EUR) is extorted from victims by gangs that operate ransomware scams. However, this is a conservative estimate. The real number is likely much higher.

Symantec researchers highlight the fact that ransomware gangs might come in conflict with cybercriminals that rely on traditional malware. That’s because ransomware is not subtle, so it will automatically prompt users to thoroughly clean their devices of malware infections.

Experts report that many pieces of ransomware are served via advertisements on adult websites. That’s why users are advised to avoid clicking on such ads.

Furthermore, internauts must ensure that their computers are fully patched and running an antivirus.