Serious Discussion Default Deny Tools and Script Interpreters in the AI Era

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Hi everyone,

After the massive ransomware waves subsided a decade ago, it felt like individual users didn't need to worry about malware as much anymore. I rarely heard about widespread outbreaks targeting individual consumers, as threat actors might shift their focus primarily to corporate networks.

However, I came across a concerning post on a Chinese forum today titled: "Avoid using Bing search for now; it's flooded with phishing sites."

The poster mentioned they were trying to download a cloud drive client (Quark) via Bing, clicked on a phishing link, and got infected with the "SilverFox" (银狐) trojan (a rampant phishing/malware family in Asia). They are currently trying to disinfect their system. They also noted that even the second search result for "Kaspersky" led to a phishing site...

Looking through the replies to that thread, two key observations stood out to me:

1. AI-driven evasion: With the advent of AI, malware variants and FUD (Fully Undetectable) techniques are evolving so fast that signature-based AVs simply cannot keep up.
2. AI-mass-produced phishing: AI is being used to mass-produce highly convincing fake websites and optimize SEO poisoning at an unprecedented scale.

It seems AI has drastically boosted malware authors' productivity, making individual users a highly profitable and easy target once again.

On the flip side, the rise of AI tools has paradoxically forced me to lower my own security posture. In the past, I heavily relied on Default Deny solutions (e.g., Appguard, NVT ERP, Excubits Bouncer, Voodooshield, Rehips, Hard_Configurator, etc; currently I have only H_C installed) to block any unauthorized binary code in user space and restricted all risky script interpreters.

However, I recently started using Google Antigravity (an AI Agent/developer tool). Like many modern AI productivity tools, it frequently invokes script interpreters, such as cscript, PowerShell, and Python, to execute tasks locally. To keep it working seamlessly, I had to disable the Default Deny SRP protection in H_C.

So here is my question: In the AI era, the risk of sophisticated attacks on individual users is increasing, yet we can no longer easily rely on traditional Default solutions to protect ourselves without breaking the new generation of AI productivity tools.

How do you view this conflict? I'd love to hear your thoughts and setups!

 

[Bot]

Hi everyone,

After the massive ransomware waves subsided a decade ago, it felt like individual users didn't need to worry about malware as much anymore. I rarely heard about widespread outbreaks targeting individual consumers, as threat actors might shift their focus primarily to corporate networks.

However, I came across a concerning post on a Chinese forum today titled: "Avoid using Bing search for now; it's flooded with phishing sites."

The poster mentioned they were trying to download a cloud drive client (Quark) via Bing, clicked on a phishing link, and got infected with the "SilverFox" (银狐) trojan (a rampant phishing/malware family in Asia). They are currently trying to disinfect their system. They also noted that even the second search result for "Kaspersky" led to a phishing site...

Looking through the replies to that thread, two key observations stood out to me:

1. AI-driven evasion: With the advent of AI, malware variants and FUD (Fully Undetectable) techniques are evolving so fast that signature-based AVs simply cannot keep up.
2. AI-mass-produced phishing: AI is being used to mass-produce highly convincing fake websites and optimize SEO poisoning at an unprecedented scale.

It seems AI has drastically boosted malware authors' productivity, making individual users a highly profitable and easy target once again.

On the flip side, the rise of AI tools has paradoxically forced me to lower my own security posture. In the past, I heavily relied on Default Deny solutions (e.g., Appguard, NVT ERP, Excubits Bouncer, Voodooshield, Rehips, Hard_Configurator, etc; currently I have only H_C installed) to block any unauthorized binary code in user space and restricted all risky script interpreters.

However, I recently started using Google Antigravity (an AI Agent/developer tool). Like many modern AI productivity tools, it frequently invokes script interpreters, such as cscript, PowerShell, and Python, to execute tasks locally. To keep it working seamlessly, I had to disable the Default Deny SRP protection in H_C.

So here is my question: In the AI era, the risk of sophisticated attacks on individual users is increasing, yet we can no longer easily rely on traditional Default solutions to protect ourselves without breaking the new generation of AI productivity tools.

How do you view this conflict? I'd love to hear your thoughts and setups!

You are describing a real tension: the safest consumer setups have historically reduced “ambient execution” (Default Deny / SRP / AppLocker-style control), while many newer “AI agent” tools increase local automation by calling PowerShell, cscript/wscript, Python, Node, etc. The security answer is usually not “give up Default Deny,” but “re-scope it so the agent can work without turning your whole machine back into a permissive target.”

1) AI changed scale and polish more than the fundamentals

AI helps attackers in two very practical ways:

• Phishing and fake-site production scales faster and looks more convincing (better language, better cloning, faster iteration).
• Malware development and “variant churn” is cheaper (more builds, more loaders, more packers).

But it’s worth keeping expectations grounded: signature-only AV has been insufficient for a long time, and modern Windows defenses (cloud reputation, behavior blocking, exploit mitigations, attack surface reduction, SmartScreen, etc.) are specifically designed for fast-changing threats. The core defensive principles still hold: reduce what can execute, reduce what can launch scripts, reduce what can reach the network, and make “download + run” harder to complete.

2) Default Deny is still one of the best consumer controls — it just needs boundaries

The biggest risk introduced by agent tools is not “PowerShell exists,” but “PowerShell executes attacker-controlled content from user-writable locations” (Downloads, AppData, Temp, browser cache) or is driven by something that got tricked (SEO poisoning → user runs installer → code runs in user context).

So rather than disabling SRP entirely, the goal is usually:

• Keep blocking execution from user-writable paths (Downloads/AppData/Temp), because that’s where most consumer infections land.
• Allow only the minimum interpreters needed, and only in the safest way you can.
• Keep the agent’s working directories out of user-writable “wild” locations, or tightly control them.

If H_C’s SRP “Default Deny” breaks the agent, the practical fix is often to move from “global off” to “surgical allowances.”

3) Practical ways to resolve the conflict (in order of impact/effort)

A) Isolate the agent environment (best risk reduction)
If the tool must freely spawn script interpreters, treat it like a “dev workload” and isolate it:

• Run it inside a VM (Hyper-V / VMware) or Windows Sandbox (when feasible).
• Use a dedicated Windows user account/profile for the agent workload (separating browser cookies, saved sessions, and daily-use apps).
• Keep sensitive activities (banking, password vault admin, primary email) out of that environment.

This preserves productivity while containing the blast radius if something goes wrong.

B) Keep Default Deny, but allow only what the agent needs
Instead of disabling SRP, try to keep “no-exec from user space” and add narrowly-scoped allowances, for example:

• Allow interpreters only when launched from their signed, system locations (System32 / Program Files), but still block scripts/binaries launching from user-writable folders.
• If the agent drops helper binaries/scripts, force them into a controlled directory (e.g., under Program Files with admin-only write) rather than AppData/Temp.
• Avoid allowing broad paths like %LocalAppData% or %Temp% to execute — that’s where you lose most of the benefit.

(Exactly how to express that in H_C/SRP depends on your current rule set, but the principle is: keep user-writable execution blocked.)

C) Add script-specific hardening instead of “allow everything”
If you must permit PowerShell/cscript/python for legitimate automation, compensate with controls that limit abuse paths:

• Microsoft Defender Attack Surface Reduction (ASR) rules (where compatible) to reduce common script/macro abuse chains.
• Constrain script execution sources: only allow scripts from a specific, trusted folder; block/avoid running scripts directly from Downloads/email attachments.
• Keep SmartScreen and Defender cloud protection on (these help specifically with “newly-seen” files and fake installers).

Even when malware is “new,” reputation + behavioral controls often still catch the delivery chain (fake installer behavior, suspicious child processes, persistence, credential dumping patterns, etc.). It is not perfect, but it materially improves outcomes compared to signatures alone.

D) Reduce SEO-poisoning exposure (high value, low friction)
If search results are being poisoned (whether on Bing or any engine), the best mitigation is changing the habit pattern:

• Prefer direct vendor URLs, pinned bookmarks, or official app stores.
• On Windows, consider using winget for well-known software (when available) to avoid “search → download” entirely.
• Use an ad/script blocker and a reputable DNS filter (these often blunt malvertising and known-phishing domains).
• Treat sponsored results as untrusted and verify domains carefully before downloading anything.

This is boring advice, but it cuts off the main consumer infection path.

4) A realistic “AI-era” setup direction for power users

If you like Default Deny, a sustainable model many advanced users move toward is:

• A “daily driver” profile that stays strict (SRP/App control on; user-space execution blocked; strong browser isolation).
• A separate “automation/dev/agent” profile or VM where interpreters are permitted, but the environment is less trusted and less privileged.

That way you don’t have to choose between security and productivity on the same trust plane.

Conclusion

The conflict is real, but the best resolution is usually not lowering your whole system’s posture; it’s separating trust zones and/or keeping Default Deny while allowing only the minimum required interpreter workflows in controlled locations. If you must relax controls for an agent, isolating that agent (VM/Sandbox/separate account) is the cleanest way to keep modern productivity tools without returning to “anything in user space can run.”