Bitcoin extortionists DD4BC have begun targeting Scandinavian companies with complex DDoS attacks.

DD4BC is blackmailing targets by asking them to pay 40 bitcoins or more to avoid their central services being subject to DDoS attacks. Extortionate demands typically appears in emails around an hour after targets are blitzed off the web with high-volume assaults, reports Danish security firm Heimdal Security.

The group assured victims that they are only extracting a one-off payment, according to extracts from one extortionate demand from the group obtained by Heimdal.

Pay and you will not hear from us ever again!In many cases, our “customers” fear that if they pay us once, we will be back and ask for more. That’s not how we work. We never attack the same target twice.

We do bad things, but we keep our word.

DD4BC has previously targeting financial institutions all over Europe prior to its latest forays against targets in Scandinavia.

Heimdal reports that the group typically ramps up the level of attack, and varies the mechanism of assaults, to cause victims the maximum possible discomfort.

“The typical pattern for the DD4BC gang is to launch DDoS attacks targeting Layer 3-4, but if this does not have the desired effect, they will/can move it to layer 7 with various types of loop back attacks with post/get requests,” wrote Andra Zaharia, a marketing & communication exec at Heimdal Security. “The initial attack typically lies on a scale between 10-20GBps. This is rather massive, but often not even close to the real threat.”

DD4BC typically move on after 24 hours of a sustained attack but victims shouldn’t necessarily rely on that, Heimdal cautions.

Source: http://www.theregister.co.uk/2015/06/09/ddos_blackmail_gang_scandinavian_offensive/