Trojan-Downloader:W32/Bredolab

Classification

Malware

Trojan-Downloader

W32

Trojan-Downloader:W32/Bredolab, Trojan-Downloader:W32/Bredolab, Trojan-downloader:W32/bredolab.gen!c

Summary

This type of trojan secretly downloads malicious files from a remote server, then installs and executes the files.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

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

Trojan-Downloader:W32/Bredolab is a family of trojan-downloaders that are known to download and install rogue antivirus programs - also known as rogueware - onto the infected computer. The installed rogueware generates misleading or downright false alerts, notification messages and/or scanning reports to pressure the user into "purchasing" or "activating" the rogueware in order to disinfect or remove the supposed threats. Even if the user does so however, the program may not function as intended.

Activity

During installation, Bredolab variants create the following registry entry so that the trojan-downloader runs every time Windows starts:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ "RunGrpConv" = "1"
 

It also creates the following mutex so that only one instance of the downloader will be running on the system:

  • _SYSTEM_4D2EF3A_

Currently, all the variants analyzed were found to download files from Russian websites such as those listed below:

  • http://mud[...].ru
  • http://davidbred[...].ru

The files downloaded from those websites are encrypted and will be decrypted by the trojan-downloader before being executed on the infected machine.