The Cyber Security Arms Race Just Entered a New Dimension
The term “Agentic AI” might sound like science fiction, but for those in the Thames Valley security community, it represents the most significant shift in threat capability since the introduction of cloud computing. This is not the passive, reactive AI we know-it is the arrival of autonomous, goal-driven threat actors that operate entirely without human intervention.
We are moving past adversaries using GenAI as a faster writing tool (like generating phishing emails) into a world where an AI system can conduct an entire attack lifecycle-from reconnaissance and vulnerability mapping to exploitation and lateral movement-at machine speed.
Defining the Threat: From Tool to Autonomous Attacker
To understand the challenge, we must differentiate Agentic AI from the Generative AI (GenAI) models we use daily.
• GenAI (Passive): Requires human input for every step (e.g., “Write me a phishing email about a fake invoice”). It’s a tool.
• Agentic AI (Active): Receives a single, high-level instruction (e.g., “Breach Company X’s HR database and steal all UK employee IDs”). The agent then autonomously breaks that goal down into sub-tasks, researches targets, executes the attacks, and even adapts to defences it encounters along the way, all in milliseconds.
This transition from passive tool to active attacker means two things for the security community: the time to detection will shrink dramatically, and traditional human-led defenses will become functionally obsolete against these machine-speed attacks.
The Real-World Impact: Automating the Attack Chain
For organisations in the UK, Agentic AI poses an immediate strategic threat by automating the initial access vectors that plague our networks:
1. Automated Identity Theft: An Agentic AI can rapidly synthesise open-source intelligence (OSINT), generate highly personalised deep-fake voice/video content, and execute large-scale, adaptive credential harvesting attacks with devastating efficiency. Since compromised credentials are the top initial access vector (Source: Verizon DBIR), automating this step is crippling.
2. Zero-Day Discovery and Exploitation: The AI can tirelessly probe massive codebases or network segments to find flaws and then write and deploy the exploit code instantly. This reduces the lifespan of patches and increases the pressure on proactive vulnerability management.
3. Lateral Movement: Once inside, an Agentic AI can map internal networks, escalate privileges, and find high-value assets far faster than any human operator could.
The strategic challenge is that human defenders-who still account for the majority of incident response-cannot possibly manage, investigate, and contain incidents that begin and execute at machine speed.
The Strategic Defence: Machine-Speed Resilience
Fighting fire with fire is the only viable strategic response to Agentic AI. The goal is to move from a human-reaction model to a machine-resilience model.
1. AI-Powered Automation (SOAR): Security Orchestration, Automation, and Response (SOAR) platforms are no longer a luxury; they are necessary to automate detection, triage, and containment. Your defence must also operate at machine speed.
2. Real-Time Behavioural Analytics: Traditional signature-based detection is useless. Defences must focus on analysing unusual behaviour (e.g., a service account accessing the HR database at 3 AM), not just known malicious files.
3. Governance of Trusted Systems: Strong governance over your internal GenAI agents is key. If your own internal AI is compromised and turned into an agentic attacker, the consequences are immediate and catastrophic. Treat all internal AI systems as potential insider threats (Source: Google Cloud Security).
The arrival of Agentic AI demands a fundamental shift in defence architecture. It’s a call for the Thames Valley security community to realign resource and strategy towards a defence that is autonomous, adaptive, and capable of operating outside the limits of human reaction time.
The clock is ticking at machine speed. What immediate resource reallocation or automation project are you prioritising to meet the challenge of autonomous AI attackers in 2026?
At OxCyber, we’re helping our community prepare for this new reality. Being part of OxCyber gives you access to expert insights, peer discussions, and collaborative events like our CISOx roundtables on autonomous defence strategies. Share your approach in the comments below, or contact us today to join the next session and shape the future of machine-speed resilience together.
