One of the latest versions of ransomware, CryptoWall, is reportedly spreading through Greece at an alarming rate, infecting both personal computers and corporate networks.
CryptoWall is an apparent successor to CryptoLocker, which Cybersecurity experts struggled to contend with in 2013 and 2014.
Cryptowall is a Trojan horse that encrypts files on an infected computer, rendering them inaccessible, until a ransom is paid to decrypt them. The ransom is typically demanded in Bitcoin , in which transactions can be made anonymously and without intervention by a central authority.
The CryptoLocker virus is estimated to have caused losses of $3 million.
CryptoWall appears to have hit Greece with particular intensity. "In the past several days, the situation has intensified, there are thousands of messages about the infection of corporate networks," reads a statement by the country's cybersecurity unit.
Greece happens to have been one of the places that experienced an apparent surge in bitcoin interest, expressed by businesses and individuals who were unable to withdraw cash or move money during the latest debt crisis.
Like with such viruses in the past, computer users are advised not to give into the ransom demand. Users have typically been defiant in cases where the attack consists of threats for future harm, such as a DDoS attack, or where a reward is offered for hacked information.
But in a spate of attacks on police offices several months ago, during which critical files were encrypted and inaccessible, most had to cave in. As unpleasant as it was, the encrypted files, which weren't adequately backed up, were too valuable relative to the some $500 demanded.
Extortionists demanding bitcoins from supposed users of Ashley Madison, whose user database was hacked in the summer, have had limited success.