Bluesky has confirmed that its recent day-long outage was caused by a distributed denial-of-service (DDoS) attack, in which junk traffic was used to overwhelm the social network's servers. The company disclosed the cause in a post on Monday, stating it had upgraded its defences and was continuing to monitor the situation, though it did not share further technical details. This marks the latest disruption to hit the platform, raising fresh concerns about the resilience of its infrastructure against coordinated online attacks.

DDoS attacks typically work by flooding a target's servers with overwhelming volumes of traffic, often generated using networks of hijacked devices such as botnets or residential proxy networks. Security researchers monitoring the incident on a public forum reported that Iran-backed attackers had claimed responsibility, amid a broader rise in Iranian attacks on US businesses and infrastructure since the outbreak of the US and Israel-led war earlier this year. This is not the first such incident for Bluesky, which suffered a similar prolonged series of outages from a comparable traffic flood in April; it remains unclear whether the two attacks are connected.