HSTSPreloadBot is a bot in the security scanners category, operated by Chromium.
Checks that links can be preloaded for Chromium
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.
HSTSPreloadBot identifies itself with this user agent string:
hstspreload-botAnyone 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 HSTSPreloadBot 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: hstspreload-bot Disallow: /
User-agent: hstspreload-bot Disallow: /private/ Disallow: /search
User-agent: hstspreload-bot Allow: /blog/ Disallow: /
User-agent: hstspreload-bot Allow: / User-agent: * Disallow: /
User-agent: hstspreload-bot group, HSTSPreloadBot ignores your User-agent: * rules, so repeat any that should still apply.hstspreload-bot from HSTSPreloadBot's user agent; check Chromium'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 HSTSPreloadBot if it is a service you use, and keep its visits out of page views and ad requests either way.
Transfon Security for publishersHSTSPreloadBot is not a person. Exclude it from campaign and conversion data so reports reflect real visitors.
Transfon Security for advertisersAllow HSTSPreloadBot only if it works for your store, and keep it away from cart and checkout.
Transfon Security for e-commerceIf HSTSPreloadBot 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 HSTSPreloadBot 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
HSTSPreloadBot is a bot in the security scanners category, operated by Chromium. Checks that links can be preloaded for Chromium
We have not confirmed whether HSTSPreloadBot 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: hstspreload-bot" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "hstspreload-bot" at your WAF. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so HSTSPreloadBot may not follow it, and anyone can send HSTSPreloadBot's user agent, so a fake HSTSPreloadBot 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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