Kimwolf v7 Hides DDoS Traffic Behind Chrome Fingerprints and Ethereum
August 12, 2026 
Palo Alto Networks Unit 42 discovered Kimwolf v7 on February 3, 2026, while hunting threats following public disclosures of the botnet’s earlier activity.
The new version substantially upgrades the DDoS capabilities and command infrastructure of a botnet that has been targeting Android TV boxes since August 2025, while its Linux counterpart AISURU has been active since mid-2024. The operators’ core objective hasn’t changed, build a large-scale DDoS platform, but the methods for sustaining it and hiding its traffic have become considerably more sophisticated.
“This version upgrades its distributed denial-of-service (DDoS) attack capabilities and the resilience of its command-and-control (C2) infrastructure. Kimwolf primarily affects Android TV boxes and set-top boxes.
Kimwolf v7 adds an HTTP/2-based DDoS flood that constructs complete browser fingerprints. This makes attack traffic more difficult to distinguish from legitimate browsing.” reads the report by Palo Alto Networks.
“The threat’s binary includes five hard-coded public Ethereum-based endpoints for resolving Ethereum Name Service (ENS) domains. ENS is a blockchain-based naming system used to obtain C2 addresses.”
The nghttp2 library powers the HTTP/2 flood and constructs headers that mirror legitimate Chrome browser behavior at the protocol level, making rate-limiting and fingerprint-based DDoS mitigation significantly harder.
On top of that, the botnet uses Ethereum’s naming service to resolve its command server address, querying five legitimate public blockchain RPC endpoints shuffled randomly before each attempt, which means blocking any individual endpoint does almost nothing.
“Kimwolf also carries a hard-coded Tor .onion hidden service as a backup and a local proxy architecture for flexible routing between clearnet and Tor.” continues the report. “The malware developers added this function to directly respond to C2 server takedown efforts in December 2025.”
The three-tier structure, Ethereum ENS, then Tor hidden service, then local proxy on 127.0.0.1:23075, is a direct operational response to two takedowns the botnet suffered in December 2025. The local proxy routes all C2 traffic through the same local address regardless of whether it’s going to the clearnet or Tor, which means the proxy component can be updated independently without redeploying the main bot binary. Unit 42 also identified what it assesses with moderate confidence to be an operator-controlled RPC facade at eth.rpcuniverse.com, based on its single-tenant hosting, registration timing, and exclusive presence in Kimwolf samples.
Kimwolf spreads by abusing residential proxy services to reach Android TV boxes that ship with Android Debug Bridge enabled on port 5555. Once tunneled into a local network through a proxy endpoint, attackers can install the malware without any authentication. The botnet masks itself as “netd_service” to blend in with legitimate Android system processes, and Unit 42 found eight APK packages distributed between October and December 2025 that masquerade as a system service called SystemService, probing for root access before executing a bundled kernel payload.
Version 7 also strips out all scanning, exploitation, and brute-force functionality from the main binary — the operators have separated the propagation pipeline from the DDoS core. External loaders now handle initial access, while the Kimwolf binary handles attacks and acts as a relay. The attack method count was consolidated from 43 text-named commands in earlier versions to 15 numbered methods covering layers 3 through 7, including the new HTTP/2 flood, a high-performance UDP flood with ARM NEON SIMD acceleration optimized for the processors in Android TV boxes, and a TLS/HTTPS flood. Unit 42 clustered C2 infrastructure across 22 IP addresses in Saint Petersburg, Russia, all sharing the same SSH host key between December 2025 and February 2026.
The defensive guidance from Unit 42 is straightforward: treat Android TV boxes as untrusted devices and segment them from enterprise networks. Disabling ADB or restricting it to USB-only access removes the primary way this botnet gets onto devices. For detection, watch for outbound HTTPS connections to Ethereum RPC endpoints from devices that normally have no business touching blockchain services, Tor circuit activity or SOCKS5 proxy traffic from TV boxes, connections to localhost port 23075, and any Android consumer device running a process named “netd_service.”
“Kimwolf v7 is a focused evolution of an already large-scale botnet. The HTTP/2 flood with Chrome browser fingerprinting complicates application-layer DDoS mitigation, as attack traffic now mirrors legitimate browser behavior at the protocol and header level.” concludes the report. “The three-tier C2 system (Ethereum ENS, Tor .onion, local proxy) indicates that the operators are investing in infrastructure built to withstand takedown operations.”
In March, the U.S. DoJ disrupted command-and-control infrastructure used by several IoT botnets, including AISURU, Kimwolf, JackSkid, and Mossad. The operation involved authorities from Canada and Germany, along with major tech companies, to target botnet operators and weaken their global cybercrime activities.
The AISURU/Kimwolf botnet was linked to a record-breaking DDoS attack that peaked at 31.4 Tbps and lasted just 35 seconds. Cloudflare said the November 2025 incident was part of a surge in hyper-volumetric HTTP DDoS attacks observed in late 2025, all automatically detected and mitigated.
Kimwolf is a newly discovered Android botnet linked to the Aisuru botnet that has infected over 1.8 million devices and issued more than 1.7 billion DDoS attack commands, according to XLab.
The Kimwol Android botnet primarily targets TV boxes, compiled using the NDK and equipped with DDoS, proxy forwarding, reverse shell, and file management functions. It encrypts sensitive data with a simple Stack XOR, uses DNS over TLS to hide communication, and authenticates C2 commands with elliptic curve digital signatures. Recent versions even incorporate EtherHiding to resist takedowns via blockchain domains.
Kimwolf follows a naming pattern of “niggabox + v[number]”; versions v4 and v5 have been tracked. By taking over one C2 domain, researchers observed around 2.7 million IPs interacting over three days, indicating a likely infection scale exceeding 1.8 million devices. Its infrastructure spans multiple C2s, global time zones, and versions, making it hard to estimate the total number of infections.
The botnet borrows the code from the Aisuru family, however, operators redesigned it to evade detection. Its primary function is traffic proxying, though it can execute massive DDoS attacks, as seen in a three-day period issuing 1.7 billion commands between November 19 and 22.
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Pierluigi Paganini
(SecurityAffairs – hacking, Kimwolf v7)
