GEN:SID 1:614
Message BACKDOOR hack-a-tack attempt
Summary hack-a-tack is a Trojan Horse.
Impact Possible theft of data via download, upload of files, execution of files and reboot the targeted machine.
Detailed Information This Trojan affects the following operating systems:

    Windows 95
    Windows 98
    Windows ME
    Windows NT
    Windows 2000
    Windows XP

The Trojan changes system registry settings to add the hack-a-tack server to programs normally started on boot. Due to the nature of this Trojan it is unlikely that the attacker's client IP address has been spoofed.

    SID    Message
    ---    -------
    141    HackAttack 1.20 Connect
    614    hack-a-tack attempt

This Trojan is commonly used to install other Trojan programs.

The server portion opens TCP ports 31785 and 31787 and UDP ports 31789 and 31791 by default to establish a connection between client and server. The ports may then be configured by the attacker to use something other than these defaults.
Affected Systems  
Attack Scenarios This Trojan may be delivered to the target in a number of ways. This event is indicative of an existing infection being activated. Initial compromise can be in the form of a Win32 installation program that may use the extension ".jpg" or ".bmp" when delivered via e-mail for example.
Ease of Attack This is Trojan activity, the target machine may already be compromised. Updated virus definition files are essential in detecting this Trojan.

The Trojan server is located at <drive>:\WINDOWS\Expl32.exe.
Corrective Action Edit the system registry to remove the extra keys or restore a previously known good copy of the registry.

Affected registry keys are:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\

Registry keys added are:

    Explorer32 ="<drive>:\windows\Expl32.exe"
    Configuration Wizard = "<drive>:\windows=cfgwiz32.exe"

Removal of this entry is required.

Delete the file(s) <drive>:\WINDOWS\Expl32.exe and <drive>:\windows=cfgwiz32.exe

Ending the Trojan process is also necessary. A reboot of the infected machine is recommended.
Additional References Whitehats arachNIDS
http://www.whitehats.com/info/IDS314
http://www.whitehats.com/info/IDS504

Hackfix.org
http://www.hackfix.org/miscfix/hackatack.shtml

Commodon Communications
http://www.commodon.com/threat/threat-hack.htm
Rule References arachnids: 314