WORM_FLYSTUD.AC

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 adds 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.)

It drops the following copies of itself into the affected system:

• %System%\{random name1}\{random filename}.EXE

(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.)

Autostart Technique

This worm drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\{Random file name}.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

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=Recycle.exe
shell\1=´ò¿ª(&O)
shell\1\Command=Recycle.exe
shell\2\=ä¯ÀÀ(&B)
shell\2\Command=Recycle.exe
shellexecute=Recycle.exe

Dropping Routine

This worm drops the following files:

• %System%\{random name2}\cnvpe.fne
• %System%\{random name2}\dp1.fne
• %System%\{random name2}\eAPI.fne
• %System%\{random name2}\eCompress.fne
• %System%\{random name2}\HtmlView.fne
• %System%\{random name2}\internet.fne
• %System%\{random name2}\krnln.fnr
• %System%\{random name2}\RegEx.fnr
• %System%\{random name2}\shell.fne
• %System%\{random name2}\spec.fne
• %User Profile%\Start Menu\Programs\Startup\{random filename}.lnk
• %User Temp%\E_N4\cnvpe.fne
• %User Temp%\E_N4\dp1.fne
• %User Temp%\E_N4\eAPI.fne
• %User Temp%\E_N4\eCompress.fne
• %User Temp%\E_N4\HtmlView.fne
• %User Temp%\E_N4\internet.fne
• %User Temp%\E_N4\krnln.fnr
• %User Temp%\E_N4\RegEx.fnr
• %User Temp%\E_N4\shell.fne
• %User Temp%\E_N4\spec.fne

(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 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.. %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 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 to trick the users into thinking that the dropped copy is the legitimate folder.