Rule:

--
Sid:
159

--
Summary:
This event is generated when incoming an data stream associated with the NetMetro Trojan Horse is detected.

--
Impact:
Limited control of the target host.

--
Detailed Information:
Due to the nature of this Trojan it is unlikely that the attacker's client IP address has been spoofed.

The server portion opens TCP port 5031 by default to establish a connection between client and server. This event indicates that a host external to the protected network running a NetMetro Trojan Server is communicating with a host on the protected network that may be controlling the Trojan.

--
Affected Systems:
	Windows 95
	Windows 98
	Windows ME
	Windows NT
	Windows 2000

--
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 named NMS.exe.

--
False Positives:
None Known

--
False Negatives:
None Known

--
Corrective Action:

A reboot of the infected machine is recommended. The Trojan does not start automatically at boot time nor does it change any system registry settings.

--
Contributors:
Original Rule Writer Max Vision <vision@whitehats.com>
Sourcefire Research Team
Nigel Houghton <nigel.houghton@sourcefire.com>

--
Additional References:

Whitehats arachNIDS
http://www.whitehats.com/info/IDS79

Dark-e:
http://www.dark-e.com/archive/trojans/NetMetro/index.html

--
