Gloucester City Council has warned residents that some personal information may have been stolen by Russian hackers.
The Cyber attack in December 2021 damaged the council's network and online services.
An investigation by the council and cyber incident response experts concluded that while some personal information ‘may have been taken' criminals have not published anything and are unlikely to in the future.
Seven Russian cyber criminals have been sanctioned by the UK and US Government's in relation to this and other incidents.
Gloucester's managing director, Jon McGinty, said: ‘I share the annoyance of the public that we were targeted in this way; this criminal group targeted our council among other private and public sector organisations to disrupt our public services in an attempt to extort a ransom payment from the council.
‘I am sorry for any concern this announcement may cause residents and members of the public, but would like to emphasise this occurred in December 2021 and, based on advice received from our national law enforcement partners, the council believes it is unlikely that any information taken will be released in the future.'