WORM_FLYSTUD.ERR

This worm drops copies of itself in all removable drives. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

Installation

This worm creates the following folders:

• %System%\{Random name1}
• %System%\{Random name2}
• %System%\{Random name3}
• %System%\{Random name4}
• %User Temp%\E_N4

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

Other System Modifications

This worm deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TypedURLs

Propagation

This worm drops copies of itself in all removable drives.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[AutoRun]
open=Recycled.exe
shell\1=´ò¿ª(&O)
shell\1\Command=Recycled.exe
shell\2\=ä¯ÀÀ(&B)
shell\2\Command=Recycled.exe
shellexecute=Recycled.exe

Dropping Routine

This worm drops the following files:

• %System%\{Random name1}\krnln.fnr - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\eAPI.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\dp1.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\shell.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\cnvpe.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\com.run - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\internet.fne - detected as TROJ_FLYSTUD.EIK
• %System%\{Random name1}\RegEx.fnr - detected as TROJ_FLYSTUD.EIK
• %System%\{Random name1}\spec.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\spec_a.fne - also detected as WORM_FLYSTUD.ERR
• %System%\{Random name1}\{random filename}.exe - also detected as WORM_FLYSTUD.ERR
• %User Temp%\E_N4\krnln.fnr - also detected as WORM_FLYSTUD.ERR
• %User Temp%\E_N4\eAPI.fne - also detected as WORM_FLYSTUD.ERR
• %User Temp%\E_N4\dp1.fne - also detected as WORM_FLYSTUD.ERR
• %User Temp%\E_N4\shell.fne - also detected as WORM_FLYSTUD.ERR
• %User Temp%\E_N4\cnvpe.fne - also detected as WORM_FLYSTUD.ERR
• %User Profile%\Start Menu\Programs\Startup\{Random file name}.lnk - non-malicious file

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

NOTES:
WORM_FLYSTUD.ERR

Other Details

Based on analysis of the codes, it has the following capabilities:

It also searches for folders in removable drives then drops copies of itself as {Folder name}.exe. It then sets the attribute of the original folder to Hidden, Read-Only, and System to trick the users into thinking that the dropped copy is the legitimate folder.