Ghost Security, also known as GhostSec, is a self-described "vigilante" group that was formed to attack ISIS websites that promote Islamic extremism.
[2] The group claims to have taken down hundreds of ISIS-affiliated websites or social media accounts and thwarted potential terrorist attacks by cooperating with law enforcement and intelligence agencies.
[3] On 14 November 2015, Anonymous posted a video[6] announcing its "biggest operation ever" against the terrorist group[7][8] in response to the attacks in Paris, taking down 3,824 pro-ISIS Twitter accounts[9] and doxxing recruiters.
[10] A message posted by an ISIS-affiliated account on encrypted chat service Telegram replied defiantly to Anonymous by providing instructions on how to respond to a potential cyberattack.
The group carried out the attack in support of Ukraine's struggle against Russia, with precise timing in order to avoid unnecessary casualties.