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Security tool · recon

cero

Scrapes domain names straight out of TLS certificates across IP ranges/ports - great for finding hosts that never appear in passive sources.

tlscertificatessubdomains
Stable IDtool:ceroLast updatedLast verifiedLegacy review pendingProvenanceSource-linked
Overview

Where cero fits

Scrapes domain names straight out of TLS certificates across IP ranges/ports - great for finding hosts that never appear in passive sources.

Detection-first use

Start with the least intrusive template that can distinguish your hypothesis from a normal response. Preserve raw output and a negative control.

Install

Installation references

Install with goAuthorization required
go install github.com/glebarez/cero@latest
Positive signal
Tool-specific output that supports the stated hypothesis.
Negative control
No result, or identical behavior against a known-safe control.
Intrusiveness
Review flags and target scope before execution.
Test safely

Command templates

Names from certsAuthorization required

Populate placeholders only with assets that are explicitly in scope.

cero {target} | anew certnames.txt
Positive signal
Tool-specific output that supports the stated hypothesis.
Negative control
No result, or identical behavior against a known-safe control.
Intrusiveness
Review flags and target scope before execution.
Related

Continue the workflow

TooltlsxToolsubfinder
Sources

Attribution and verification

Version history: normalized permanent page created 2026-08-20. Upstream activity and popularity are separate signals and do not establish tool safety.