Threat Descriptions

Trojan-Downloader:W32/WinFixer

Classification

Category :

Malware

Type :

Trojan-Downloader

Platform :

W32

Aliases :

-

Summary

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

Removal

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.

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 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.

Technical Details

Members of the Trojan-Downloader:W32/WinFixer malware family appear to be utility, anti-spyware or anti-malware products. When executed however, these programs report misleading or fake results, with excessive amounts of false errors. Scare tactics are then employed, as the programs ask the user whether they want to 'keep the errors' or purchase the full version of the software to 'correct the errors'.

Winfixer is made by Winsoftware. The company appears to be affiliated with Vantage Software, which claims to be headquartered in Croydon, England, but registers their website in Chile and hosts their website on servers in Canada. ErrorSafe and WinAntiSpy are two other companies who have re-branded Winfixer and offer it for sale on their sites.

Winfixer can also be found localized in languages other than English.

Installation

WinFixer malware may be silently downloaded and installed by other malware (trojans, worms, etc) or it may be manually downloaded by an unsuspecting user from the product website.

A representative variant from this family is known as DriveCleaner. When manually executed, the program displays the following installer wizard:

It then visibly downloads its installation files from remote websites (listed above) and installs them onto the system:

Some commonly used installation paths for the WinFixer family are:

  • C:\Program Files\DriveCleaner 2006 Free
  • C:\Program Files\DriveCleaner Free

Activity

On execution, the program will scan the computer system and display its scanning results. A representative screenshot of the kind of exaggerated results reported by DriveCleaner can be seen below:

Registry

DriveCleaner may add one or more of the following program auto-launch registry values:

  • DriveCleaner Free
  • DriveCleaner 2006 Free
  • SDR6_Check
  • PAS_Check
  • UDC6cw
  • Dnse

to

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run:

Network Connections

Attempts to connect to:

  • http://ulog.drivecleaner.com
  • http://ulog.fr.drivecleaner.com
  • http://adfarm.mediaplex.com/ad/bk/[..]