103.txt

This is the snapshot of Snot Latest Rules

Rule:

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Sid:
103

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Summary:
This event indicates that network activity relating to the Trojan Horse program Subseven22 has been detected. This software offers complete control of the infected host.

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Impact:
Possible theft of data and control of the targeted machine leading to a compromise of all resources the machine is connected to. This Trojan also has the ability to delete data, steal passwords and disable the machine. Other versions are capable of launching DDoS attacks.

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Detailed Information:
This is a windows exceutable that makes changes to the system registry, Win.ini and System.ini. When first executed the Trojan replicates itself and in most cases, gives the copy a random name. This Trojan may use the file extensions ".exe" or ".dll".

Subseven is an improved version of the Netbus Trojan, Subseven DEFCON8 2.1 is an improved version of Subseven that affects Windows 95 and 98 implementations.

The Trojan changes system startup files and registry settings to add the Subseven sever to programs normally started on boot.

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

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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.

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Ease of Attack:
This is Trojan activity, the target machine may already be compromised. Updated virus definition files are essential in detecting this Trojan.

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False Positives:
None Known

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False Negatives:
None Known

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Corrective Action:
This is a particularly difficult Trojan to remove and should only be attempted by an experienced Windows Administrator.

Edit the system registry to remove the extra keys or restore a previously known good copy of the registry.

Affected registry keys are:

HKEY_CLASSES_ROOT\exefile\shell\open\command
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\RunServices
HKEY_LOCAL_MACHINE\Hardware\Data
HKEY_LOCAL_MACHINE\Hardware\Enum
HKEY_LOCAL_MACHINE\Software\Microsoft\DirectXMedia

Registry keys added are:

HKEY_CLASSES_ROOT\.dl

Removal of the replicant is also required, look for files ending in ".exe" or ".dll" in the <drive>:\Windows\ or <drive>:\Windows\System\ folders that use alphanumeric file names. The name of the replicant may be in one of the registry keys above.

A machine reboot is required to clear the existing process from running in memory.

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Contributors:
Original Rule Writer Max Vision <[e-mail]>
Sourcefire Vulnerability Research Team
Nigel Houghton <[e-mail]>

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Additional References:

McAfee
http://vil.mcafee.com/dispVirus.asp?virus_k=10566
http://vil.nai.com/vil/content/v_10566.htm

Symantec Security Response
http://securityresponse.symantec.com/avcenter/venc/data/backdoor.subseven22.html

F-Secure:
http://www.f-secure.com/v-descs/subseven.shtml

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