Redirected hosts file

Classification

Spyware

Other

W32

Redirected hosts file

Summary

This detection is triggered when an entry in your hostsfile redirects a particular IP address to a different host. A redirected hostsfile entry is a common action performed by various malware.

Removal

Automatic action

Once detected, the F-Secure security product will automatically handle a harmful program or file by either blocking or asking the user for a desired action.

Exclude an intentionally modified hosts file

Based on the settings of your hosts file that has been intentionally modified by the user will still trigger this detection. In such cases, you can exclude the hosts file from further scanning. To do so:

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

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User Guide

See the user guide for your product on the Help Center.

Contact Support

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Submit a sample

Submit a file or URL for further analysis.

Technical Details

A hosts file is a 'directory' of hostnames and their IP addresses that is used by the operating system to easily find resources, such as other computers or websites.

Maliciously modified hosts file

Modifying and redirecting hosts file entries is a common tactic used by malware to silently send users to an unwanted website. Often, this is used to expose the user's machine to web-based attacks, as well as exposing the user to unsolicited and/or malicious content.

In other cases, the modification is made to prevent the user from accessing certain sites, such as operating system or security software vendors.

Intentionally modified hosts file

Under certain circumstances, hosts files may be manually modified by system administrators or developers in the course of their work.

Such intentional modifications will still trigger the 'redirected hosts file' detection. In such cases, to preserve the modification, the user should exclude the hosts file from scanning once the product detects the change (see section Removal: Exclude an intentionally modified hosts file).