UK firms as part of a `` systematic '' global hacking operation , a new report has revealed . The attacksAttack.Databreachwere found to have breachedAttack.Databreacha wide variety of secret data ranging from personal data to intellectual property , in what the report described as `` one of the largest ever sustained global cyber espionage campaigns '' . The group behind the attacks , named APT10 , was found to have used custom malware and `` spear phishingAttack.Phishing`` techniques to target managed outsourced IT service companies as stepping stones into the systems of an `` unprecedented web '' of victims according to the report 's authors . The report 's authors included the National Cyber Security Centre ( NCSC ) and cyber units at defence group BAE systems and accountancy firm PwC . The gang were found to have used the companies as a way into their customers ' systems from 2016 onwards , although there is evidence to suggest they had first employed the tactics from as early 2014 . PwC cyber security Partner Richard Horne told the Press Association the extent of the malicious campaign was still unclear . He said : `` The reason we 've gone public with this is because we can see so much and we have seen so much in several managed IT service providers ( MSPs ) and other companies compromised through it , but we do n't know how far this has gone . `` Us , together with the NCSC and BAE Systems are very keen to get this information out there so we can promote a mass response to this . '' The report behind the unmasking operation , codenamed Cloud Hopper , highlights targeted attacks against Japanese commercial firms and public bodies , but indicates further widespread operations against companies in 14 other countries including the UK , France and the United States . The report 's authors state APT10 is `` highly likely '' to be based in China , demonstrating a pattern of work in line with China Standard Time ( UTC+8 ) and the targeting of specific commercial enterprises `` closely aligned with strategic Chinese interests '' . Mr Horne said the data collectedAttack.Databreachin individual attacks spanned a plethora of sensitive categorisations . He said : `` We 've seen a number of different companies targeted for different reasons , but essentially it 's all around sensitive information they hold , whether that 's intellectual property , or personal information on people or a whole realm of other areas . `` It 's a very large-scale espionage operation . '' Spear phishing emails with bespoke malware were first sentAttack.Phishingto staff in targeted companies , and once the attackers had successfully infiltrated their systems they were free to seek outAttack.Databreacha raft of sensitive data within . Dr Adrian Nish , head of threat intelligence at BAE , told the BBC such MSPs were crucial to the nature of the campaign 's success . He said : `` Organisations large and small rely on these providers for management of core systems and as such they can have deep accessAttack.Databreachto sensitive data '' . `` It is impossible to say how many organisations might be impacted altogether at this point . '' The organisations behind operation Cloud Hopper are expected to release a further report this week into the detailed methods that ATP10 has used in its campaign in a bid to encourage firms to take a proactive approach into checking if their systems have been targeted .