Rotherham Council’s IT system was attacked by criminals exploiting the outbreak of the coronavirus.
Another authority said Rotherham’s IT system had been compromised, but Rotherham denied this.
Assistant director for customer, information and digital services, Luke Sayers, said: “A member of staff unintentionally clicked on an internet link in a spam email which resulted in some automatic emails being generated.
“No data or information was compromised, and this issue was quickly resolved.
“We regularly remind staff to be vigilant when opening external emails from unknown sources and to follow advice from our Information Governance training.”
The alarm was sounded by Middlesbrough Council, which says local authorities are being targeted with fake emails.
An IT office in another local authority sent an email to colleagues warning them.
“It seems that criminal organisations are taking the opportunity to exploit the outbreak of the coronavirus,” he said.
“ICT are aware of another local government organisation, Rotherham Council, that has been compromised due to an email using the subject of COVID-19 as a cover.
“As a result, their email system has been compromised. If you receive any emails from Rotherham Council with subjects such as ‘Payroll Adjustment’ and ‘COVID-19’ can you inform ICT immediately.
“Do not attempt to open it or click on any links contained within — 95 per cent of all email coming into the council network is spam and junk and is filtered out before it reaches your inbox.
“However, whilst ICT teams work continuously to ensure we maintain a strong security posture we cannot be complacent. So we’re asking you to be extra vigilant when opening and accessing emails.”