sublert: monitoring new subdomains deployed by specific organizations and issued TLS/SSL certificate

by do son · Published June 8, 2019 · Updated June 8, 2019

Sublert is a security and reconnaissance tool that was written in Python to leverage certificate transparency for the sole purpose of monitoring new subdomains deployed by specific organizations and issued a TLS/SSL certificate. The tool is supposed to be scheduled to run periodically at fixed times, dates, or intervals (Ideally each day). New identified subdomains will be sent to Slack workspace with a notification push. Furthermore, the tool performs DNS resolution to determine working subdomains.

Sublert is mainly built for bug bounty hunters hacking on broad scopes to step up their reconnaissance game and beat the competition by gaining early access to new subdomains. However, Sublert could also be used internally as part of an AppSec program to monitor various subdomains deployed by the engineering team.