Rick Wang , an official with Taiwan ’ s Financial Supervisory Commission ( FSC ) , said each brokerage had received an email setting a deadline for the transfer of funds to avoid a distributed denial of service ( DDoS ) attack . They have become common tools for cyber criminals trying to cripple businesses and organizations with significant online activities . “ We have never seen this on such a scale - five companies hit at one time with the same threat , ” said Wang , adding that the regulator usually sees single instances of cyber-crime . FireEye , a cybersecurity consultancy , said the attacks were similar to a wave of threatened denial of service attacks by a previously unidentified group that first appeared in Europe last month . The Taiwan attacks do not pose a threat to the island ’ s broader trading and financial system , Wang said , but he added that the regulator had asked all securities firms to step up defensive measures . “ The emails were sent under the name of the ‘ Armada Collective ’ , ” said Chiu Shao-chou , an official of the internet cybercrime division of Taiwan ’ s Criminal Investigation Bureau , the government ’ s top investigation body . The Armada Collective , a hacking extortion group , has been linked to financial blackmail heists elsewhere . But Chiu said the group has been put under watch and Taiwan investigators were still looking into the original source of the emails . The email demanded payment Attack.Ransom in web-based digital currency bitcoin equivalent to about T $ 300,000 ( $ 9,731.41 ) , Taiwan media said . None of the securities companies made any payments Attack.Ransom , Chiu said . Another brokerage firm , Capital Securities Corp , was hit on Monday by a DDoS attack lasting 20 minutes before its system recovered , the regulator said , but it did not link the latest case to the threatening emails