Mocbot.A

Summary

Mocbot is an IRC bot that can spread using a vulnerability in Windows Plug and Play service (MS05-039).

Disinfection & Removal

Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see Removal Instructions.

Technical Details

Installation to system

The bot's file is a PE executable 7846 bytes long, packed with MEW file compressor.

When the bot's file is started, it copies itself as 'wudpcom.exe' file to Windows System folder and then creates a service with following attributes:

Service path: wudpcom.exe

Service name: Windows UDP Communication

Service short name: wudpcom

Description: Provides communication between clients and servers over UDP. If this service is stopped, UDP communication between clients and servers on the network will be impaired. If this service is disabled, any services that explicitly depend on it will fail to start.

Bot functionality

When the bot is active, it connects to an IRC server, joins a certain channel and acts as a bot there.

The following IRC servers are used by the bot:

 bbjj.househot.com
 ypgw.wallloan.com
 
 

The bot joins to password-protected IRC channel where the hacker can send commands to the bots to control infected computers. Several tasks can be performed, including the following:

 * perform SYN and UDP flood
 * download and execute files
 * start command shell
 * scan and exploit computers vulnerable to MS05-039
 
 

Spreading using MS05-039

The bot scans for random IP addresses and exploits a vulnerability in Windows Plug and Play service (MS05-039).

Info on this PnP vulnerability is available here:

http://www.microsoft.com/technet/security/Bulletin/MS05-039.mspx

The vulnerability can be exploited via 139/TCP and 445/TCP.

Detection

F-Secure Anti-Virus detects this worm with the following updates:

Detection Type: PC
Database: 2005-10-23_01