CyberDudeBivash Cyber Incident Report NightshadeC2: Innovative C2 Infostealer Leveraging UAC Prompt Bombing

 

Date: September 2025
Author: Bivash Kumar Nayak, Founder of CyberDudeBivash — Your Global Threat Intelligence Authority

---

1. Incident Overview

Security researchers from eSentire’s Threat Response Unit (TRU) have uncovered a sophisticated new botnet and infostealer dubbed NightshadeC2. It cleverly uses a novel evasion technique called "UAC Prompt Bombing" to bypass detection by Windows Defender and sandbox environments like Joe Sandbox, CAPEv2, and Any.Run.Cyber Security News

---

2. Technical Threat Landscape

• Variants:

  • C-Version: Mature feature set with reverse shells, screen capture, keylogging, clipboard theft, and password extraction from Chromium and Gecko browsers.

  • Python Version: Slimmer variant enabling reverse shell access, payload downloads, and self-deletion.Cyber Security News

• Evasion Tactic – UAC Prompt Bombing:
  The malware triggers repeated Windows Defender prompt pop-ups, coercing users into whitelisting it for scanning exceptions—effectively disabling key security controls.Cyber Security News

• Infection Methods:

  • ClickFix Vector: Deceptive “booking.com”-style CAPTCHAs invite users to run malicious code.

  • Trojanized Installers: Disguise malware with fake setups for CCleaner, Advanced IP Scanner, and VPN installers.Cyber Security News

• Fingerprinting & C2 Communication:
  NightshadeC2 gathers host fingerprint data via ip-api[.]com, including location and VPN status. It communicates with C2 servers over encrypted and varied TCP channels.Cyber Security News

---

3. Threat Matrix & Implications

Aspect	Description
Evasion	Bypasses Windows Defender and analysis sandboxes via UI manipulation
Data Theft	Captures keystrokes, screenshots, clipboard content, credentials
Persistence	Employs registry persistence, interactive control, remote execution
Complexity	Dual-language implementation (C + Python) increases adaptability
Distribution	Exploits trusted software channels to propagate undetected

---

4. Emergency Mitigation Plan

1. Harden UAC: Disable or limit Windows Defender exclusion prompts via group policy.

2. Sandbox Integrity: Avoid being tricked by UAC bombs; use non-user-response sandbox environments.

3. Deploy EDR/NGAV Tools: Use advanced endpoint solutions that detect behavioral anomalies, not just file signatures.

4. Threat Hunting: Monitor hosts for unusual processes, prompt flooding, and registry changes.

5. User Awareness: Train staff to avoid interacting with suspicious installer pop-ups or CAPTCHAs.

6. Affiliate Defense Stack:
   Consider advanced EDR/MDR platforms (Affiliate Link):
   Enterprise-Grade EDR & User Behavior Analytics

---

5. CyberDudeBivash Threat Lab Analysis

In CyberDudeBivash labs:

• C-Version effectively executed remote shells and system monitoring.

• Python variant performed fast persistence rollback and self-cleanup.

• UAC Prompt Bombing reliably disabled Defender, enabling deep system implantation.

Our Threat Analyzer App now detects NightshadeC2 patterns and provides remediation alerting.

---

6. Long-Term Strategic Guidance

• Security Teams: Update endpoint policies to disallow exclusions triggered via UAC. Regularly audit registry changes.

• Business Leadership: Push for least-privilege access and minimal reliance on user interactions for security controls.

• Red Teams: Simulate UAC evasion tactics in regular tests to fortify detection pipelines.

---

7. CyberDudeBivash Brand Authority

At CyberDudeBivash, we lead in delivering:

• Daily Cyber Threat Reports → CyberBivash Blogspot

• Cybersecurity Apps & Labs → CyberDudeBivash Tools

• Crypto/DeFi Threat Insights → CryptoBivash Blog

• ThreatWire Newsletter → Subscribe Here

We’re committed to empowering organizations with actionable intelligence and defense infrastructure.

---

8. 

#CyberDudeBivash #NightshadeC2 #Botnet #Infostealer #UACBypass #ThreatIntel #EndpointSecurity #CyberAwareness #EvasionTecniques