Russian hackers have been linked to the cyber attack which has knocked out several online services at Gloucester City Council.
The local authority became aware their IT systems had been affected on December 20.
And since then, the council’s online revenue and benefits, planning and customer services have been affected.
The council has been working with the National Crime Agency and the National Cyber Security Centre to understand more about the attack.
But the problem could take up to six months to resolve as affected servers and systems need to be rebuilt.
Councillors and officers were given an update about the investigation last week.
And council sources, who do not wish to be named, say the cyber attack was carried out by hackers in the former Soviet Union.
Insiders also say the malware made its way into the local authority’s system embedded in an email sent to a council officer.
This harmful software, known as sleeper malware, is understood to have been dormant for some time before it was activated last month and wreaked havoc among the council’s systems.
The issue is so serious that other local authorities in Gloucestershire and government agencies have taken preventative action and are currently blocking emails coming from the city council.
The interactive online application forms used to claim for housing benefit, council tax support, test and trace support payments and discretionary housing payments are currently unavailable.
Residents are instead being asked to contact the council via email and there is information on their website detailing how people can use these services.
However, due to the cyber attack, the council’s planning application website is also unavailable and there are delays to several services.
Opposition councillors have raised concerns over the impact the cyber attack is having on the council.
Liberal Democrat group leader Jeremy Hilton (Kingsholm and Wotton) said: “Just before Christmas the city council’s computer systems and servers were compromised by a cyber attack.
“This is the second time, in ten years, that this has happened.
“The council closed down its servers and is working hard to rebuild its information technology systems.
“It has made sure benefits and its staff are paid. However, it is currently no longer possible to check your bin day, use ‘find your councillor’ or pull off the records of previous council meetings from its website.
“Interrogation of planning applications or commenting on them cannot currently be done online.
“Experts are working with the council to recover its computer systems.
“Councillors and officers can still be contacted by email. It may be some time before things are back to normal. There are a lot of questions that still need to be answered.”
Labour group leader Terry Pullen (Moreland) also said he was really concerned about the effect the cyber attack is having on the council’s ability to deliver many of its services.
“I know that there is an investigation going on to try and find out what has gone wrong and that council officers are doing all they to deliver essential services as best they can,” he said.
“What worries me most is that there seems to be no indication as to when IT systems will return to normal and how long this will impact on both the public and local businesses.
“Obviously a cyber incident like this is likely to incur considerable extra costs and considering the continual budget cuts to city council services it is far from clear how this will be paid for.”
Council leader Richard Cook (Con, Kingsway) said the local authority was doing everything it can to fix the problem and minimise its impact on residents.
“I appreciate the concerns about this incident and want to reassure residents that we’re doing all we can to address the situation as quickly as possible,” he said.
“Our staff are working very hard to minimise the impact to residents and to our services.
“However, we’re asking people to be patient while we work with the National Cyber Security Centre and the National Crime Agency to find out more about the incident.
“All the information that residents need about services affected is on the website and they can contact customer services if they require further assistance.”
