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Cisco Talos header artwork for its NIK C2 report, showing a hooded figure behind two laptops with padlock icons.
Image: Cisco Talos (fair use).

Threat Intel

Cisco Talos Says NIK C2 Is an AI-Enabled C2 Framework Whose Windows Implant Calls OpenAI From the Compromised Host, Streams Keystrokes and Can Lock the Screen for Bitcoin or USDT

The Go implant talks over a TLS WebSocket with a 250-millisecond HTTP fallback, can bill OpenAI against the victim's own API key, and grew from a stealer into a full framework with HVNC, AMSI bypass and bootkit staging between Aug. 12 and Aug. 17. Talos published ClamAV coverage and C2 path IOCs.

Priya Shah, Threat IntelSingapore6 min read

SINGAPORE - Cisco Talos said Thursday that it has found a new command-and-control framework in the wild, NIK C2, whose Windows implant carries its own client for OpenAI's Chat Completions API, so an operator can send prompts to a large language model from inside a compromised session and have the answers returned through the same encrypted channel.

The implant also streams keystrokes live, dumps browser credentials, Discord tokens and cryptocurrency wallets, and can lock a victim's screen with a ransom demand in Bitcoin or USDT. Talos said the framework "reshapes adversary tradecraft by collapsing collection and exploitation into a single continuous session, effectively erasing the offline processing delays that historically granted defenders critical detection windows."

A Go implant that talks to OpenAI

NIK C2's implant is a Go-based, 64-bit Windows remote access tool. It keeps a TLS WebSocket open on port 443 and falls back to an HTTP polling loop every 250 milliseconds, encrypting traffic with AES-256-GCM derived from a hardcoded seed. To survive takedowns, Talos said, it can rotate across three C2 tiers: runtime-updated URLs, an embedded encrypted server list and a hardcoded fallback address.

Talos diagram of the NIK C2 implant's operational architecture, including the OpenAI Chat Completions path.
Image: Cisco Talos (fair use).Figure 1 in the report, the implant's dual-channel C2 and AI path.

The AI feature is an `ai_generate` command. The implant pulls a prompt, an optional API key and a model name from the C2 payload, posts them to `https://api.openai.com/v1/chat/completions`, and returns the model reply, the model name and the token-usage object to the operator. If the operator leaves the API key blank, the implant reads `OPENAI_API_KEY` from the victim's environment. The default model when none is specified is gpt-4. The whole round trip runs with a 60-second timeout. OpenAI's billing and access logs, Talos noted, would show the victim's key, not the actor's.

Samples Talos examined were compiled with Go 1.23.4 and carried an embedded build path under `/opt/nik_panel/data/`, identifying the project as "nik_panel." During the research window Talos observed a live server at 87.120.196[.]120, resolving total-sitevv[.]lol, with a TLS certificate whose Common Name was set to nik-panel.

How the family grew

Talos timeline of NIK C2 implant versions from Aug. 12 to Aug. 17, 2026.
Image: Cisco Talos (fair use).Figure 2, the three versions Talos mapped from first sightings.

Talos mapped three versions from first-sighting dates in open sources. Version 1, first seen Aug. 12, 2026, already had a keylogger, reverse proxy, screen capture and Discord token grabber. Version 2, Aug. 14, added HVNC, RDP session hijacking, AMSI and UAC bypasses and Telegram and Discord stealers. Version 3, Aug. 17, brought the OpenAI GPT-4 integration, audio and video capture, and the screen-locking ransomware and MBR-backup features. All of the binaries had Zeroed PE TimeDateStamp fields and near-epoch filesystem timestamps that show up as Nov. 29, 1979.

What to hunt for

The implant's command surface is large: Talos counted more than 52 commands, covering credential and Wi-Fi theft, live keylogging, screen and camera capture, clipboard interception, SOCKS5 and reverse proxy tunnels, RDP operations, registry Run key persistence, a self-healing watchdog, AMSI patching, process hollowing, the AI generate call, and a screen-locking ransomware path that writes lock_screen.html and lock_start.bat, then creates a Run key named SystemLock. The ransomware does not encrypt files. A separate bootkit preparation module runs bcdedit and Confirm-SecureBootUEFI, then stages a 16-byte placeholder named bootkit.bin that spells "NIK_BOOTKIT_PREP" in ASCII.

PowerShell AMSI bypass script Talos recovered from the NIK C2 implant.
Image: Cisco Talos (fair use).Figure 13, the implant's AMSI bypass PowerShell stub.

On launch the implant can rename itself to csrss.exe in the Windows temp directory, write itself under %AppData%\Roaming\Microsoft\Network, set a critical-process flag that can blue-screen the machine if the process is killed, and check for a debugger. Persistence includes a registry Run key and, for privilege escalation, a fodhelper.exe COM hijack under HKCU\Software\Classes\ms-settings\Shell\Open\command.

For network hunting, Talos listed the implant's C2 endpoints: /api/c2/update for beacons, /api/c2/result for command output, /api/c2/screen for screenshots, /api/c2/file_chunk for file exfiltration, /api/c2/rproxy_up for reverse-proxy traffic and /api/c2/ws for the WebSocket command channel. Every message uses the same AES-256-GCM scheme. Endpoint signals include a process claiming to be svchost.exe or simvol.exe, a Run key named SystemLock, and outbound traffic from a host that also talks to api.openai.com with a Chat Completions payload. ClamAV coverage is Win.Trojan.GoDiscorder-10060526-0, and Talos published a fuller IOC set on its GitHub repository.

Sources:


Priya Shah covers threat intelligence, intrusion analysis, and adversary tradecraft for SOCtember from Singapore.

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