Masscan is a bot in the security scanners category.
Masscan is an open source internet scale port scanner. Requests with this name come from mass scans of the internet.
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.
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 Masscan 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: Masscan Disallow: /
User-agent: Masscan Disallow: /private/ Disallow: /search
User-agent: Masscan Allow: /blog/ Disallow: /
User-agent: Masscan Allow: / User-agent: * Disallow: /
User-agent: Masscan group, Masscan ignores your User-agent: * rules, so repeat any that should still apply.Masscan from Masscan's user agent; check the operator'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 Masscan if it is a service you use, and keep its visits out of page views and ad requests either way.
Transfon Security for publishersMasscan is not a person. Exclude it from campaign and conversion data so reports reflect real visitors.
Transfon Security for advertisersAllow Masscan only if it works for your store, and keep it away from cart and checkout.
Transfon Security for e-commerceIf Masscan 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 Masscan 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
Masscan is a bot in the security scanners category. Masscan is an open source internet scale port scanner. Requests with this name come from mass scans of the internet.
We have not confirmed whether Masscan 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: Masscan" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "Masscan" at your WAF. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so Masscan may not follow it, and anyone can send Masscan's user agent, so a fake Masscan 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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