[Courtesy of Shinhan Bank]
South Korean banks are on guard against an attack from cyber criminals claiming to be the Armada Collective who have sent extortion demands by email, demanding bitcoin ransoms.
With the help of state experts, seven South Korean commercial lenders including KB Kookmin, Woori and Shinhan heightened their cyber security after hackers threatened to launch a Distributed Denial of Service (DDoS) attack unless they receive about 360 million won (314,410 US dollars) in ransom payment by Monday.
The threat on Wednesday put South Korean financial authorities and state security experts on alert to thwart a possible DDoS attack. Armada Collective' hackers have been known for sending email extortion demands promising DDoS attacks. Not much is known about the group, and it is impossible to tell if those behind Wednesday's email demand are real, or simply cyber criminals pretending to be the Armada Collective.
There have no known cases in which South Korean banks have paid bitcoin ransoms, though they have been the target of alleged cyber attacks by North Korean hackers.
Last week, Nayana, a web hosting company attacked by Erebus, paid 1.3 billion won (1.1 million US dollars) in bitcoins in return for having its infected Linux servers decrypted. Erebus is a type of malicious software that prevents or limits users from accessing their system until they pay in bitcoins.
Lim Chang-won = cwlim34@ajunews.com
reporter
Park Sae-jin
swatchsjp@ajunews.com
![[OLY] Hackers attack Olympic server: Yonhap](https://image.ajunews.com/content/image/2018/02/10/20180210143108298821.jpg)