Classification

Category :

Malware

Type :

-

Aliases :

Asylum, Backdoor.Asylum

Summary

Asylum is a simple backdoor that works on Windows 9x/ME, NT/2000. The backdoor is located in the windows directory and called 'winmp32.exe'. When run it installs itself and sends a notification to the author about the infected machine using ICQ web interface. The service then runs on TCP port 81 and accessible from anywhere if the machine has direct Internet connection.

Removal

Removal instructions:

- delete the backdoor file from Windows directory

- remove the registry and win.ini entries mentioned above

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

It supports the following commands:

- password authentication (required before the other commands)
- remove the backdoor from the system
- reboot the machine
- print Windows directory
- print Windows system directory
- upload a file to the machine
- run a program on the machine
 

For installation it has many ways of modifying the system. It chooses from them using internal variables set by the author.

It can create keys under

'[HKLM]\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SystemAdministration'
'[HKLM]\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices\SystemAdministration'
 

Other way is to modify win.ini to look like this:

[Windows]
load=winmp32.exe
run=winmp3.exe
[boot]
shell=explorer.exe winmp32.exe