When using Safari or other browsers, tap the ‘share’ icon, then tap the ‘Report Phishing’ option. Or, to report a phishing message in iMessage, long-press the message, tap ‘Copy…’, then tap the Netcraft icon.

In the Netcraft app, simply tap the report (clipboard) icon in the home screen. Or, from a browser, find the ‘share’ option, and share the site with the Netcraft app.

You can also use report.netcraft.com to report malicious sites from any device.

The size of the iOS app can vary based on your device, as the App Store dynamically adjusts the app download to match your device. In addition, the disk space used by the app can also vary based on the feeds you’re subscribed to. Typically the size of the iOS app once installed and configured is 80–95MB.

The size of the Android app is significantly smaller than the iOS app, due to a simpler protection mechanism. This means savings can also be made by not needing to include instructional videos showing the user how to enable the app. Typically the size of the Android app is between 2–6MB.

Unfortunately caller IDs are relatively easy for a fraudster to fake. This makes blocking calls or messages by caller ID tricky, as it can become difficult to distinguish between a fraudster using a faked caller ID and an official company using a legitimate caller ID.

For example, if you received an SMS message from a fake ‘Example Bank’, it is difficult to block that caller ID without also blocking all calls and SMS messages from the legitimate ‘Example Bank’.

The Netcraft Extension provides comprehensive site information and cybercrime protection when browsing the web. Users can also use the extension to report URLs they believe to be malicious to Netcraft. More information can be found on the browser page.

There are several reasons why you may receive a warning about a website you know to be harmless. The Extension has several built-in safety checks that will alert you if a URL contains suspicious characters, or a page is possibly susceptible to Cross-Site Scripting (XSS) attacks. In these cases, if you are sure that the website poses no threat, you can ignore the warning by clicking ‘Visit anyway’ on the block page. If you believe that the Extension has incorrectly classified a safe site as malicious, you can let us know by using the ‘Report mistake’ link on the block page. You can also access the form directly. The Extension will only ever warn you about suspicious websites by displaying a warning dialog; it will never cause the site to stop responding or display a ‘file not found’ page. Please be certain that the Extension is displaying such a warning before contacting us.

The Risk Rating displayed by the Netcraft Extension offers a further level of protection against new sites that are not yet in Netcraft’s database. A lower risk rating is better as it indicates lower risk. Although some sites contain entirely benign content, the Netcraft Extension may assign a high Risk Rating because it could be hosted under a newly registered domain, the site may have never been seen in the Netcraft Web Server Survey before, or the network hosting the site may have hosted a number of fraud sites in the past. Many other factors are also taken into account. Hosting a web site on an unusual port number will also increase the Risk Rating, as will hosting a site from a raw IP address, as many phishing sites employ this tactic. The Risk Rating can be calculated fast enough to be performed for arbitrary sites as people visit them, and does not rely on manual categorization.

‘New Site’ means the site you are currently visiting has not been seen before by the Netcraft Web Server Survey. This indicates that the site is very new and should be considered less trustworthy than other sites, since most phishing sites spring up overnight and disappear just as quickly.

The Extension displays the location of a site’s IP address based on the information provided by your computer. If your local DNS cache was ‘poisoned’ such that the a web site pointed to an IP address located in Russia, then the Extension would report the site as being located in Russia.

The Netcraft Extension functions correctly with ordinary web proxies. A small number of Internet Service Providers (ISPs) use transparent proxies to route your web page requests. This could cause the Extension to report a web site as belonging to your ISP, however, this is quite a rare occurrence.

The Netcraft Extension is available for Mozilla Firefox, Google Chrome, Opera and Microsoft Edge; no other web browsers are supported at this time.

Credential leak detection is one of the techniques the extension uses to detect shopping site skimmers. When your browser sends a request, the extension checks to see if you've entered any sensitive data (such as a credit card number or a password) into the web page. If you have, the extension inspects the outgoing request. If the request is sending the details you entered to a different domain (for example, from a netcraft.com web page to example.com) then this indicates a potential skimming attack. The request is blocked to protect your private information and you are shown a block page notifying you of the attack. The infected page is also automatically reported to Netcraft.

Before reporting any bugs, please ensure that you are using the latest version of the Netcraft Extension.

Please contact us, giving as much information as possible so that we are able to reproduce and fix the issue.