Worm:W32/BadTrans.B, W95/Badtrans.B@mm, I-Worm.BadtransII


Badtrans.B email worm was found in several locations in Europe on 24th of November 2001. This worm sends variably named attachments which might execute automatically when the emails are viewed. Badtrans.B spreads on Windows 32-bit systems, sending email messages with infected attached files, as well as installing spying trojan component to steal information from infected systems.

  1. If you don't have F-Secure Anti-Virus (FSAV from now on) you can download a trial version from our website: https://www.europe.f-secure.com/download-purchase/
  2. If you already have F-Secure Anti-Virus or if you are using a trial version, please download the latest updates from our website: https://www.europe.f-secure.com/download-purchase/updates.shtml
  3. Download and apply Microsoft's security patch against automatic activation of email attachments: https://www.microsoft.com/windows/ie/downloads/critical/q290108/default.asp
  4. Download and run F-Secure's special patch file that disables starting of Badtrans.b worm when Windows runs: ftp://ftp.europe.f-secure.com/anti-virus/tools/bt_b_dis.reg

When you click on this link your web browser will ask you if you want to open it or save it to disk. Select 'Open' option and click 'Ok' button.

  • Restart your system.
  • Scan all your hard drives with F-Secure Anti-Virus. Use 'Scan All Files' option. Set 'Confirm Operations' option if you have FSAV
  • Set 'Ask After Scan' option if you have FSAV
    • When FSAV detects the Badtrans worm in 'kernel32.exe' file in your Windows System folder, select 'Delete' disinfection action. This will remove the worm's file from your system.
    • When FSAV detects 'Trojan.PSW.Hooker' in a file (usually KDLL.DLL file), try to delete it by selecting 'Delete' disinfection option. If the file was deleted successfully then your system is clean from Badtrans worm and Hooker trojan

      If the file can't be deleted (locked by Windows), you will have to delete it manually. First, write down the location and file name of a file that FSAV detected as 'Trojan.PSW.Hooker'. Then, depending on your operating system do the following:

      For Windows 95/98 users

      If you have Windows 95 or 98, restart your system in MS-DOS mode, and type at command prompt 'DEL' followed by a space and a location of trojan file you put down before. Then press 'Enter' and the trojan file will be deleted.For Windows ME users

      If you have Windows ME, you will need to boot your computer with a system diskette and type at command prompt 'DEL' followed by a space and a location of trojan file you put down before. Then press 'Enter' and the trojan file will be deleted. It is also advised to disable System Restore function of Windows ME as the worm and trojan files can re-appear. Here are the instructions on how to disable System Restore feature: https://www.europe.f-secure.com/v-descs/sfc_dis.shtml

      For Windows NT4/2000/XP users

      If you have Windows NT, 2000 or XP please rename the trojan's file using your Windows Explorer. Rename the file with a different name, 'trojan.000' for example and restart your system. Then scan your system with FSAV and when FSAV detects the trojan in the file earlier renamed by you select 'Delete' disinfection action. This will remove the trojan's file from your system.

    • VERY IMPORTANT! If FSAV detects an infection in your email database (PST, MDB and other files), DO NOT delete this file or you will loose all your emails. You will need to delete all infected messages from your email database using your email client and then to compact these databases to purge deleted emails. After that FSAV will not find infected message any more.
  • After disinfection it is recommended to scan your system with FSAV again to ensure that no infected files are left.
  • It is also recommended to change your Windows domain password and RAS password as they might have been compromised.

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.

For more Support


Find the latest advice in our Community.

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.