A new Mirai-based IoT botnet, dubbed Aisuru, was used to launch multiple high-impact DDoS attacks exceeding 20Tb/sec and/or 4gpps.
In October 2025, the Aisuru Mirai-based IoT botnet launched massive DDoS attacks of over 20Tb/sec, mainly targeting online gaming, cybersecurity firm Netscout reports.
The botnet uses residential proxies to reflect HTTPS DDoS attacks. Its nodes are mainly consumer routers, CCTV/DVRs, and other vulnerable CPE devices, with operators continuously seeking new exploits to expand the botnet.
Acting as a DDoS-for-hire service, Aisuru avoids government and military targets, but broadband providers faced serious disruptions from attacks exceeding 1.5Tb/sec from infected customer devices.
“Aisuru and related TurboMirai-class IoT botnets have launched DDoS attacks exceeding 20Tb/sec and 4gpps, primarily related to online gaming activities.” reads the report published by Netscout. “The term “TurboMirai” is used to describe this general class of Mirai-variant DDoS botnets capable of generating multi-tb/sec and -gpps direct-path DDoS attacks.”
Like other TurboMirai botnets, Aisuru incorporates additional dedicated DDoS attack capabilities and multi-use functions, enabling operators to carry out other illicit activities, including credential stuffing, artificial intelligence (AI)-driven web scraping, spamming, and phishing.
Attacks use UDP, TCP, and GRE floods with medium-sized packets and randomized ports/flags. Over 1Tb/sec traffic from compromised CPEs disrupts broadband, and 4gpps+ floods have caused router line card failures.
“Both high-bandwidth (large packets, high bps) and high-throughput (small packets, high pps) DDoS attacks have been observed. UDP and TCP direct-path flooding capabilities default to medium-size packets in the 540–750-byte range, balancing bps and pps. Small-packet/high-pps attacks of 4gpps and above have overwhelmed line cards of chassis-based routers and layer-3 switches, causing them to drop off chassis backplane fabrics and disrupting bystander traffic. In some cases, BCPs intended to protect network infrastructure equipment may not have been fully implemented.” continues the report. “Outbound and crossbound (east-west) DDoS attacks are often as disruptive as inbound attacks.”
Netscout highlights that Aisuru and TurboMirai-class IoT botnets mainly launch single-vector, direct-path DDoS attacks, occasionally joining multivector attacks with other DDoS-for-hire services. Attacks include UDP floods with medium-to-large or smaller packets, TCP floods with small or large packets, and up to 119 TCP flag combinations. Some traffic mimics legitimate HTTP packets, while HTTPS attacks use onboard residential proxies. The researchers pointed out that the botnet traffic is not spoofed due to lack of privileged access and source-address validation on most networks.
“These botnets cannot generate spoofed DDoS attack traffic, allowing traceback and correlation with subscriber information that can be utilized to identify, quarantine, and remediate compromised devices.” continues the report.
Network operators should monitor all edges, customer, peering, and large endpoint networks, for inbound and outbound DDoS traffic. Detection, classification, and traceback systems should be active and integrated into defenses and testing. Identifying compromised devices allows remediation, but C2 disruptions may lead to recompromise. Mitigation uses intelligent systems for targeted suppression and infrastructure-based methods like Flowspec or S/RTBH, applied carefully to avoid overblocking critical traffic.
“Comprehensive defense requires instrumentation of all network edges with outbound/crossbound suppression equal in priority to inbound mitigation. Intelligent DDoS mitigation systems (IDMSs), network infrastructure best current practices (BCPs) such as infrastructure ACLs (iACLs), and proactive remediation of abusable CPE are essential.” Netscout concludes.
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