Summary

Wootbot represents the growing family of backdoors - hacker's remote access tools. These tools allow to contol victims' computers remotely by sending specific commands to them. Also these backdoors can steal data and spread to computers vulnerable to exploits. In addition Wootbot is capable of working as a proxy and can use strong encryption of its connections. This variant of Wootbot contains the new MYSQL exploit.

Disinfection

F-Secure provides the special disinfection utility to eliminate WootBot backdoor infection. You can download this utility from our ftp site:

http://www.f-secure.com/tools/f-bot.zip

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.zip

The unpacked version is available here:

http://www.f-secure.com/tools/f-bot.exe

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.exe

Disinfection instructions can be found here:

http://www.f-secure.com/tools/f-bot.txt

ftp://ftp.f-secure.com/anti-virus/tools/f-bot.txt

F-Secure Anti-Virus starting from version 5.40 can disinfect a computer infected with Wootbot automatically by renaming the backdoor's file. A computer has to be restarted to complete disinfection.

Manual disinfection for Wootbot backdoor requires renaming of an infected file, usually located in Windows or Windows System folder and restarting a system. Please note that the backdoor's file may have read-only, system and hidden attributes, so Windows Explorer has to be configured to show such files.

If the infection is in a local network, please follow the instructions on this webpage:

http://www.f-secure.com/v-descs/netdisinf.shtml

Additional Details

When the backdoor's file is run, it copies itself as POOLCLL.EXE file to Windows System folder. Then the backdoor installs a service named 'evmon' (display name: 'Event Monitor'). The backdoor's file is started with '-netcvs' parameter.

When active, the backdoor starts an FTP server on a random port.

The backdoor can be controlled remotely and do any of the below:

 - start socks4/5 proxy
 - start http proxy
 - scan/exploit for vulnerabilities
 - ping flood
 - open command shell
 - download/execute files

The backdoor contains the following scanners/exploits:

 - ipc (remote shares), port 139
 - mssql (Microsoft SQL servers), port 1433
 - mysql, port 3306
 - DCOM1 (DCOM RPC), ports 135, 445, 1025
 - LSASS (MS04-011), port 445
 - ftp_scan (remote ftp sites), port 21

The backdoor can spread to local networks. It contains a lot of usernames/passwords that are used in a dictionary attack.

Additionally the backdoor steals CD keys from games and other software.

Detection

F-Secure Anti-Virus currently detects this Wootbot backdoor variant generically as 'Backdoor.Win32.Wootbot.gen'. Exact detection for this variant will be added as 'Backdoor.Win32 Wootbot.al' soon.

Writeup: Alexey Podrezov, January 28th, 2005;

Technical Details: Jarkko Turkulainen, January 28th, 2005;