LetSEncrypt is a bot in the security scanners category, operated by Let's Encrypt.
Let's Encrypt domain control validation service.
Security scanners probe sites for vulnerabilities, certificates and exposed services. Some are research projects, some are vendors you hired. Allow your own scanners and block the rest at the WAF.
LetSEncrypt identifies itself with this user agent string:
Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)Anyone can copy a user agent string. Transfon Security also checks where each request comes from, so a request that claims to be a known crawler but comes from the wrong network is treated as a fake, not as the real crawler.
We have not confirmed whether LetSEncrypt follows robots.txt. Add a rule, then check your logs to see that it stopped. robots.txt is a plain text file at the root of your domain, such as https://example.com/robots.txt.
User-agent: LetSEncrypt Disallow: /
User-agent: LetSEncrypt Disallow: /private/ Disallow: /search
User-agent: LetSEncrypt Allow: /blog/ Disallow: /
User-agent: LetSEncrypt Allow: / User-agent: * Disallow: /
User-agent: LetSEncrypt group, LetSEncrypt ignores your User-agent: * rules, so repeat any that should still apply.LetSEncrypt from LetSEncrypt's user agent; check Let's Encrypt's own documentation if it publishes a different robots.txt name.Treat robots.txt as a statement of your policy, and enforce it where requests arrive.
Allow LetSEncrypt if it is a service you use, and keep its visits out of page views and ad requests either way.
Transfon Security for publishersLetSEncrypt is not a person. Exclude it from campaign and conversion data so reports reflect real visitors.
Transfon Security for advertisersAllow LetSEncrypt only if it works for your store, and keep it away from cart and checkout.
Transfon Security for e-commerceIf LetSEncrypt is a service you use, allow it on the endpoints it needs and block it elsewhere.
Transfon Security for SaaS and APIsrobots.txt is a request, not an enforcement. Transfon Security shows LetSEncrypt by name in the Top Bots report, so you can see how often it visits and which pages it reads. Block or allow it with a User Agent rule, or slow it down with a rate limit decision rule.
Transfon Security
LetSEncrypt is a bot in the security scanners category, operated by Let's Encrypt. Let's Encrypt domain control validation service.
We have not confirmed whether LetSEncrypt follows robots.txt. Add a robots.txt rule, then check your logs to see that it stopped, and block it by user agent if it did not.
Add "User-agent: LetSEncrypt" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "https://www.letsencrypt.org" at your WAF. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so LetSEncrypt may not follow it, and anyone can send LetSEncrypt's user agent, so a fake LetSEncrypt ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.
Security scanners probe sites for vulnerabilities, certificates and exposed services. Some are research projects, some are vendors you hired. Allow your own scanners and block the rest at the WAF.
Transfon Security identifies every bot in this directory in your traffic reports, flags fake search crawlers, and lets you allow, block or rate limit each bot.
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