YahooCacheSystem is a bot in the link preview bots category, operated by Yahoo.
YahooCacheSystem caches website contents as part of the Yahoo! Search Service.
Link preview bots fetch a page when someone shares its URL in a chat app or social network, to build the preview card. Blocking them breaks your link previews, so keep them allowed but leave them out of analytics and ad requests.
YahooCacheSystem identifies itself with this user agent string:
YahooCacheSystem; YahooWebServiceClientAnyone 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 YahooCacheSystem 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: YahooCacheSystem Disallow: /
User-agent: YahooCacheSystem Disallow: /private/ Disallow: /search
User-agent: YahooCacheSystem Allow: /blog/ Disallow: /
User-agent: YahooCacheSystem Allow: / User-agent: * Disallow: /
User-agent: YahooCacheSystem group, YahooCacheSystem ignores your User-agent: * rules, so repeat any that should still apply.YahooCacheSystem from YahooCacheSystem's user agent; check Yahoo'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.
YahooCacheSystem fetches pages when your links are shared or syndicated. Keep it allowed so previews and feeds work, but leave it out of page views and ad requests.
Transfon Security for publishersWhen ads or posts are shared, YahooCacheSystem fetches the landing page. Those hits are not clicks, so keep them out of campaign reports.
Transfon Security for advertisersProduct links shared in chats and feeds are fetched by YahooCacheSystem. Keep it allowed so previews show the right image and price.
Transfon Security for e-commerceAllow YahooCacheSystem on public pages so shared links preview well, and keep it off the app.
Transfon Security for SaaS and APIsrobots.txt is a request, not an enforcement. Transfon Security shows YahooCacheSystem 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
YahooCacheSystem is a bot in the link preview bots category, operated by Yahoo. YahooCacheSystem caches website contents as part of the Yahoo! Search Service.
We have not confirmed whether YahooCacheSystem 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: YahooCacheSystem" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "YahooCacheSystem" at your WAF. In Transfon Security that is one User Agent block rule.
No. robots.txt is voluntary, so YahooCacheSystem may not follow it, and anyone can send YahooCacheSystem's user agent, so a fake YahooCacheSystem ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.
Link preview bots fetch a page when someone shares its URL in a chat app or social network, to build the preview card. Blocking them breaks your link previews, so keep them allowed but leave them out of analytics and ad requests.
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.
Privacy, security, monetization, and performance insights. A few emails a month, no spam.