An anonymous reader writes: "A botnet of over 25,000 bots is at the heart of recent DDoS attacks that are ferociously attacking businesses across the world with massive Layer 7 DDoS attacks that are overwhelming Web servers, occupying their resources and eventually crashing websites," reports Softpedia. This botnet's particularity is the fact that attacks never fluctuated and the attackers managed to keep a steady rhythm. This is not a classic botnet of infected computers that go on and off, but of compromised CCTV systems that are always on and available for attacks. The brands of CCTV DVRs involved in these attacks are the same highlighted in a report by a security researcher this winter, who discovered a backdoor in the firmware of 70 different CCTV DVR vendors. These companies had bought unbranded DVRs from Chinese firm TVT. When informed of the firmware issues, TVT ignored the researcher and the issues were never fixed, leading to crooks creating this huge botnet.