the target ’ s webmail credentials . Then , in early 2016 , the Callisto Group began sendingAttack.Phishinghighly targeted spear phishing emails with malicious attachments that contained , as their final payload , the “ Scout ” malware tool from the HackingTeam RCS Galileo platform . Scout was , ironically , originally developed for law enforcement . “ These spear-phishing emails were craftedAttack.Phishingto appear highly convincing , including being sentAttack.Phishingfrom legitimate email accounts suspected to have been previously compromisedAttack.Databreachby the Callisto Group via credential phishingAttack.Phishing, ” F-Secure noted in a paper , adding that the group is continuing to set up new phishingAttack.Phishinginfrastructure every week . One of the targets for Callisto in 2016 was the Foreign Office , according to BBC sources . The outlet reports that the government is investigating an attack that began in April last year . A source told the BBC that the compromised server didn ’ t contain the most sensitive information , fortunately . In a statement , the UK 's National Cyber Security Centre ( NCSC ) declined attribution or comment and merely said : `` The first duty of government is to safeguard the nation and as the technical authority on cybersecurity , the NCSC is delivering ground breaking innovations to make the UK the toughest online target in the world . The government 's Active Cyber Defence programme is developing services to block , prevent and neutralise attacks before they reach inboxes. ” F-Secure also said that evidence suggests the Callisto Group may have a nation-state sponsor , and that it uses infrastructure tied to China , Russia and Ukraine . It told the BBC that Callisto Group 's hacking efforts show similarities in tactics , techniques , procedures and targets to the Russia-linked group known as APT28 , though the two appear to be different entities . However , Callisto Group is also associated with infrastructure used for the sale of controlled substances , which “ hints at the involvement of a criminal element , ” F-Secure said . Going a bit further , a different source told the BBC that two of the phishing domains used in the UK attackAttack.Phishing“ were once linked to an IP address mentioned in a US government report into Grizzly Steppe. ” Grizzly Steppe is the code-name for Russian meddling in the US elections .