A hacker group going by the name of "Phantom Squad" is threatening to take down Xbox Live and PSN over the 2015 holiday season.

Posting on Twitter, the group said "Xbox Live and PSN is vulnerable to attacks," and asked if its followers were "ready for a great holiday".

The tweets also seemed intended to antagonise Lizard Squad, the group responsible for last Christmas' takedown of the popular online gaming networks.

Phantom Squad claims to have attacked targets such as Steam, The Elder Scrolls Online, Star Wars: The Old Republic, and Grand Theft Auto Online, and says it took Reddit offline earlier this week.

Supposedly, the intended DDoS attacks - flooding servers with traffic in order to overwhelm them - are designed to demonstrate a lack of cybersecurity.

Online gaming networks are attractive targets for hackers at Christmas, given the increased traffic due to holidays from work and gifted games and consoles.