On December 10 2018, from 4:50 to 6:48 PM Mountain Standard Time, Netsyms experienced a Distributed Denial of Service attack targeting our main website, netsyms.com. We quickly noticed the attack and immediately began rolling out mitigations, including allocating extra CPU and RAM resources and dropping traffic from IP addresses exhibiting malicious behavior. The web server targeted was unable to serve requests for several minutes at a time during the attack.
The attack consisted of repeatedly requesting the Netsyms homepage as fast as possible from multiple devices, which hid behind Tor exit nodes to avoid being traced back to the source. There are simple tools available online to perform such an attack. There may also have been a SYN flood attack at the same time as the HTTP-based attack.
See below for a timeline.