Encrypted messaging provider Threema hit by large-scale DDoS attacks

Encrypted messaging provider Threema experienced significant service disruptions last week due to a series of large-scale distributed denial-of-service (DDoS) attacks. The attacks rendered the service unavailable for several hours on Tuesday and caused intermittent outages on Wednesday morning, impacting users' ability to connect, with further coverage provided by Cyber Insider.

The attacks, which began Tuesday evening and continued into Wednesday, targeted both Threema and its Swiss colocation partner, Nine. The encrypted messaging provider experienced downtime between 7:30 p.m. and 11:30 p.m. CEST on Tuesday, with intermittent interruptions resuming Wednesday morning. Threema stated that the attacks' continuously changing traffic sources and patterns complicated mitigation efforts. Normal operations were restored by 12:23 p.m. on Wednesday.

Threema emphasized that the incidents affected service availability, not the security of user data, as DDoS attacks aim to overwhelm infrastructure without granting access to internal systems. The company is implementing specialized upstream DDoS protection and plans to enhance its status page with an incident history and RSS feed to improve transparency for future service disruptions.

Source: Cyber Insider