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Rule Reference

SEC704lintai-ai-securitystablehookdeny

Hook script: screen capture exfiltration

Hook script captures and exfiltrates a screenshot or desktop image

Provider
lintai-ai-security
Surface
hook
Scope
per_file
Tier
stable
Severity
deny
Confidence
high
Detection
structural
Remediation
message_only

Activation Model

Preset Membership

This rule is part of the builtin activation graph through these preset memberships.

basemembership

Lifecycle

Stable Lifecycle Contract

State

stable_gated

Graduation rationale

Matches explicit screen capture utilities combined with remote transfer behavior in executable hook lines.

Deterministic signal basis

HookSignals command-line analysis over non-comment hook lines for explicit screen capture utilities such as `screencapture`, `scrot`, `gnome-screenshot`, `grim`, `maim`, `grimshot`, ImageMagick `import -window root`, or PowerShell `CopyFromScreen`, combined with remote sinks such as `curl`, `wget`, `scp`, `rsync`, `nc`, or HTTP(S) endpoints.

Malicious corpus
hook-screen-capture-exfil
Benign corpus
cursor-plugin-clean-basic
structured evidence required remediation reviewed
Canonical note

Structural stable rule intended as a high-precision check with deterministic evidence.

Nearby Signals

Related Rules

SEC201Hook script: remote code executionHook script downloads remote code and executes ithookstable
SEC202Hook script: secret exfiltrationHook script appears to exfiltrate secrets through a network callhookstable
SEC203Hook script: insecure HTTP secret sendHook script sends secret material to an insecure http:// endpointhookstable
SEC204Hook script: TLS verification disabledHook script disables TLS or certificate verification for a network callhookstable
SEC205Hook script: hardcoded auth in network callHook script embeds static authentication material in a network callhookstable
SEC206Hook script: base64 payload executionHook script decodes a base64 payload and executes ithookstable

Why It Matters ​

Capturing the desktop and sending it to a remote destination is high-confidence surveillance and data theft behavior.

What Triggers ​

SEC704 matches executable hook lines that invoke explicit screen capture utilities such as screencapture, scrot, gnome-screenshot, grim, grimshot, maim, ImageMagick import -window root, or PowerShell CopyFromScreen, and also transmit data to remote sinks such as curl, wget, scp, rsync, nc, or HTTP(S) endpoints.

False Positives ​

Shared committed hooks should not capture and transmit screenshots. Legitimate screenshot sharing should be deliberate user action, not hidden repo automation.

Remediation ​

Remove screenshot capture and remote transfer behavior from the shared hook and keep screen data local unless the user explicitly chooses to share it.