Classification

Category :

Malware

Type :

Worm

Aliases :

Myfib.H, Worm.Win32.Myfip.h

Summary

Myfip.H is a variant of Myfip family of worms. This variant doesn't propagate itself.

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

Installation to system

When run, the worm copies under %SYSTEM% directory using the name 'kernel32dll.exe'. It creates a mutex named 'Meteo/EA[DCA]'. It installs the following registry key to ensure it will be executed next time the system is started:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Distributed File System" = "kernel32dll.exe"
 

The worm also creates a thread that adds the above registry key again if it is deleted.

If the worm is running under Windows NT-based system, it tries to inject code in address space of Explorer.exe. The injected code re-executes worm's file if the process terminates. The implementation seems to be quite unstable and it might crash Explorer.exe.

Collecting files

Myfib.H collects files from all fixed and remote drives. The following list of file extensions are collected:

dwg
doc
pdf
sch
pcb
dwt
dwf
max
mdb
 

The following directories are skipped:

WINNT
WINDOWS
I386
PROGRAM FILES
ALL USERS
RECYCLER
SYSTEM VOLUME INFORMATION
INETPUB
DOCUMENTS AND SETTINGS
WUTEMP
MY MUSIC
 

If the worm doesn't find any files, it terminates. The collected files are sent to remote server at address 'saap.vicp.net', using on TCP port 34330.

Hiding the process

If the worm is running on Windows NT-based computer, it tries to hide its process by manipulating kernel data structures. This works only it worm is run under administrator privileges. If the system is Win9x-based, the worm tries to hide the process by issuing Win32 API call 'RegisterServiceProcess'.