Million of users reported they could not access X on Monday, according to available data from tracking website Downdetector.com.
The owner, Musk also claimed that either a large coordinated group or a country was involved, or both.
He wrote on the platform: “There was (still is) a massive cyberattack against X.
“We get attacked every day, but this was done with a lot of resources. Either a large, coordinated group and/or a country is involved. Tracing…”
Musk also unveiled on Fox News that IP addresses involved in the cyber attack were traced to locations “in the Ukraine area”.
The US government has recently revoked some access to satellite imagery for Ukraine and paused intelligence sharing, piling pressure on Kyiv as President Trump seeks a swift end to the war with Russia.