A National Cyber Security Centre (NCSC) spokesperson said the organisation provided guidance to affected councils.
They told the Local Democracy Reporting Service: “Whilst DDoS attacks are relatively low in sophistication and impact, they can cause disruption by preventing legitimate users from accessing online services.”
Salford and Bury councils said residents were still able to access services in person and over the phone while their websites were out of use.
Trafford Council said personal data “remained secure throughout”, adding: “We continue to remain vigilant and monitor for cyber threats.”
Tameside Council was also contacted for comment.
Councils in Greater Manchester also suffered a cyber attack in August when housing websites for Manchester, Salford and Bolton were hit in a phishing scam incident targeting thousands of people around the region.
Users were sent emails asking for personal data, with town halls warning people to check bank accounts for any suspicious activity, and change passwords which they had used to access the housing register.