Symantec reports that ransomware such as CryptoLocker is eight times more common now than in January 2014 with file-encrypting ransomware increasing 700 percent from January to August 2014.
ISTR had reported a 500 percent increase in ransomware from January to December 2013. This year, ransomware levels peaked in March, and then declined due to the GameOver Zeus botnet in late May. CryptoDefense has become the most common ransomware over the past few months, and by the end of July, it made up 77 percent of all file encrypting ransomware this year.
According to FBI estimates from June, CryptoLocker infected around 545,000 computers worldwide between September 2013 and May 2014, which led to the cybercriminals gaining £16 million. Whilst active, CryptoLocker was so successful, that even now that it has been neutralised, many similar viruses have been created with the same aims. Since CryptoLocker and GameOver Zeus, security firms have developed a service allowing victims to regain access to files without giving in to the hacker's demands.
.exe and .doc files with .exe attachments were the most frequently used malware types sent in these emails. Some 29 percent of the spear-phishing emails were sent to manufacturing enterprises, one of the most targeted industries.