Summary

Myfip.H is a variant of Myfip family of worms. This variant doesn't propagate itself. Most likely it is dropped by some other myfip-related malware.

Myfip.H also has some rootkit functionality. It tries to hide its process by manipulating operating system kernel data structures. For being successful, it requires administrator privileges.

Additional 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'.

Detection

[FSAV_Database_Version] Version=2005-02-25_01

Technical Details: Jarkko Turkulainen; Mar 3rd, 2005;