ZeroHour

Search: “Adaptive DDoS Protection”

4 stories

DDoS Attacks Cause Major Threema Outages

Sustained distributed denial-of-service attacks knocked Swiss secure messenger Threema offline for hours before upstream filtering restored service; On-Prem users unaffected.

Threema suffered a series of large-scale DDoS attacks that left its Swiss secure messaging service unavailable for about four hours Tuesday evening, with intermittent outages into Wednesday morning until restoration at 12:23 p.m. CEST. Attacks also targeted colocation partner Nine and kept changing patterns, complicating mitigation. Threema deployed additional upstream DDoS protection on August 14 and plans status page improvements; Threema On-Prem customers running their own infrastructure were unaffected.

Security Affairs · Aug 17, 2026Threat actor in the wild