WORM_IRCBOT.MC

This worm drops copies of itself into network drives. It 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.

It connects to Internet Relay Chat (IRC) servers. It opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system.

Installation

This worm drops the following copies of itself into the affected system:

• %Application Data%\taskeng.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Update System = "%Application Data%\taskeng.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Update System = "%Application Data%\taskeng.exe"

Other System Modifications

This worm creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
Windows Update System = "%Application Data%\taskeng.exe"

Propagation

This worm drops copies of itself into network drives.

It 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=usbBlock.exe
icon=%SystemRoot%\system32\SHELL32.dll,9
action=Open folder to view files
shell\open\command=usbBlock.exe
shell\open\default=1

It sends copies of itself to target recipients using the following instant-messaging (IM) applications:

• MSN

Backdoor Routine

This worm connects to any of the following Internet Relay Chat (IRC) servers:

• {BLOCKED}ate.com

It joins any of the following IRC channel(s):

• #1

It opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system.