A group of cybercriminals, calling themselves DD4BC, continues to threaten bitcoin exchanges, gaming sites and financial institutions with distributed denial of service (DDoS) attacks in order to extort bitcoins.



Akamai, the world’s leading Content Delivery Network (CDN) services provider, has reported that the “malicious” group has expanded its DDoS attacks against its customers in recent months.



"DD4BC has been using the threat of DDoS attacks to secure Bitcoin payments from its victims for protection against future attacks," said Stuart Scholly, Senior Vice President & General Manager, Security Division at Akamai. "The latest attacks – focused primarily on the financial service industry – involved new strategies and tactics intended to harass, extort and ultimately embarrass the victim publically."



The first such attack observed by Akamai was in September last year and since April 2015, the team identified 114 DD4BC attacks, including more aggressive measures that target company’s reputation through social media.



“The goal is to publicly embarrass the target, thus harming the company’s reputation and garnering more attention and credibility for its ability to create service disruptions”, the report said.



Some key observations in the report are:



The financial services sector was targeted in 58% of the attacks.



Banks and credit unions accounted for 35% of the attacks on financial services companies, 13% involved currency exchanges, and the rest were payment processing companies.



Media and entertainment companies were on the receiving end of 12% of DD4BC’s attacks, compared to 9% for online gaming and 6% for retail and consumer goods.



Akamai and its Prolexic Security Engineering and Research Team (PLXsert) will continue to monitor ongoing threats, campaigns and methodologies used by DD4BC.