Worm:W32/AutoRun.NOI

Classification

Malware

Worm

W32

W32/Autorun-jl (Sophos), Generic.dx trojan (McAfee), WORM_AUTORUN.RC (Trend Micro), W32.SillyFDC (Symantec), Worm:Win32/Emold.C (Microsoft)

Summary

A standalone malicious program which uses computer or network resources to make complete copies of itself.

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

Find the latest advice in our Community Knowledge Base.

User Guide

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

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

Worm.Win32.AutoRun.noi creates a copy of itself as the following:

  • C:\Program Files\Microsoft Common\wuauclt.exe

It creates the following registry key:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exeDebugger = "%ProgramFiles%\Microsoft Common\wuauclt.exe

Note: The key is created for automatic execution when explorer.exe is launched.

It also drops two files into the root of available removable drives:

  • autorun.inf
  • system.exe

It then injects codes to explorer.exe.

The autorun.inf file is an autorun file of system.exe and contains the following strings:

  • [autorun]open=system.exeshellexecute=system.exeshell\Explore\command=system.exeshell\Open\command=system.exeshell=Explore

Worm.Win32.AutoRun.noi attempts to retrieve information from:

  • http://druzg.ru/[...].php?v=1&rs=13441600&n=1&uid=1
  • http://drizg.ru/[...].php?v=1&rs=13441600&n=1&uid=1

The worm uses rootkit stealth techniques to hide its presence on the infected machine, including deleting its own installation file once the installation has been completed.