Abstract:
A mechanism is provided for executing an action selected by a security management device identified from an available-action list provided by the computer device. A management program module in the computer device identifies a set of actions capable of being performed on the computer device based on a state of the computer device. The management program module stores the available-action list indicative of at least one action the management program module is allowed to execute on the computer device. The management program module sends the available-action list to the security management device for a security analysis to be performed such that an action is selected from the available-action list to be executed on the computer device. Responsive to receiving the selected action from the security management device, the management program module executes the selected action on the computer device.

Description:
[0001]    This application is based on and claims the benefit of priority from Taiwan Patent Application 103112027, filed on Mar. 31, 2014. 
       BACKGROUND 
       [0002]    The present invention generally relates to a computer device, particularly to a security management device communicationally-connected to the computer device. Particularly, the present invention provides the closer interaction between the computer device and the security management device to jointly achieve better security protection. 
         [0003]    For network and information security, large enterprises or organizations have been widely adopted security information and event management (SIEM) systems. The SIEM system provides security intelligence, event response, records management, and all kinds of statements by combining events, threat and risk information together according to logs provided by a wide range of computer systems in an internal network system. 
         [0004]    For the existing SIEM system, refer to IBM&#39;s SECURITY QRADAR® SIEM or HP&#39;s ARCSIGHT SECURITY INFORMATION &amp; EVENT MANAGEMENT (SIEM). 
         [0005]    For the prior art related to SIEM, refer to, for example, WO 2013019198 or US PUB. 2011/0264608. 
       SUMMARY 
       [0006]    In one illustrative embodiment, a method, in a data processing system, is provided for executing an action selected by a security management device identified from an available-action list provided by the computer device. The illustrative embodiment identifies, by a management program module in the computer device, a set of actions capable of being performed on the computer device based on a state of the computer device. The illustrative embodiment stores, by the management program module, the set of actions as the available-action list indicative of at least one action the management program module is allowed to execute on the computer device. The illustrative embodiment sends, by the management program module, the available-action list to the security management device for a security analysis to be performed such that an action is selected from the available-action list to be executed on the computer device. Responsive to receiving the selected action from the security management device, the illustrative embodiment executes, by the management program module, the selected action on the computer device. 
         [0007]    In other illustrative embodiments, a computer program product comprising a computer useable or readable medium having a computer readable program is provided. The computer readable program, when executed on a computing device, causes the computing device to perform various ones of, and combinations of, the operations outlined above with regard to the method illustrative embodiment. 
         [0008]    In yet another illustrative embodiment, a system/apparatus is provided. The system/apparatus may comprise one or more processors and a memory coupled to the one or more processors. The memory may comprise instructions which, when executed by the one or more processors, cause the one or more processors to perform various ones of, and combinations of, the operations outlined above with regard to the method illustrative embodiment. 
         [0009]    These and other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of, the following detailed description of the example embodiments of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
           [0011]      FIG. 1  illustrates a computer system according to a specific embodiment of the present invention; 
           [0012]      FIG. 2A  illustrates a computer system according to a specific embodiment of the present invention; 
           [0013]      FIG. 2B  is a flowchart showing a method according to a specific embodiment of the present invention; 
           [0014]      FIG. 3A  illustrates a computer system according to a specific embodiment of the present invention; and 
           [0015]      FIG. 3B  is a flowchart showing a method according to a specific embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
         [0017]    As will be appreciated by one skilled in the art, the present invention may be embodied as a computer system/device, a method or a computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer-usable program code embodied in the medium. 
         [0018]    Any combination of one or more computer usable or computer readable medium(s) may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc. 
         [0019]    Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer or server may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
         [0020]    The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0021]    These computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
         [0022]    The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0023]    On one hand, the present invention provides a computer device and a security management device communicationally-connected to the computer device. Particularly, the present invention provides the closer interaction between the computer device and the security management device to jointly achieve better security protection. 
         [0024]    First, it is noted herein that the security management device in this specification is sometimes called “SIEM console” or “SIEM Manager” applicable to a computer system, especially a computer system consisting of devices configured through the intranet. The major role of the security management device is to collect logs provided by other computer devices in the computer system to provide system-wide intelligence. On the other hand, the computer device herein is sometimes called “SIEM sensor” or “SIEM agent”. The computer devices may be, for example, web server, email server, firewall device, or other network appliance generally with their own main functions to provide information services beyond the security intelligence. The hardware/software resources allocated to the computer devices are mainly used to realize their functions. Only a small amount of the resources are used to support the security management device to generate security intelligence. For example, the computer devices can generate logs when their functions are implemented to record the observed events and return the events to the security management device so that the security management device can provide security intelligence. 
         [0025]    In the prior art, when the security intelligence provided by a security management device shows specific security threats, this often relies on manual operations to take care of the other computer device in the computer system (e.g. manual shut-down, reboot, or turning off a specific communication port). Even some of the more advanced security management devices can replace manual operations, and directly issue a command to the computer device, this requires the security management device and the computer device to be tightly bound to support each other (e.g. products all belong to the same vendor), and then the security management device can know the details of the computer device such as the type, model, and actions able to perform, the operation details, and further use the proper scheme or command syntax to control the computer device. However, there are a variety of computer devices in the computer system at a general company. Also, it is possible to have new and different vendor provided computer devices at any time. Therefore, it is difficult and impractical to have the security management device support all computer devices. Another problem in the prior art is that when the security management device issues a command to a computer device, there is no consideration to the current running state of the computer device, that is, there is no consideration to whether the computer device is immediately allowed to perform an action the security management device is requesting. 
         [0026]    In view of this, it is an aspect of the present invention that a computer device provides an action list available to be executed to the security management device first, and then the security management device can select the appropriate action which currently and certainly can be performed by the computer device from the list. For example, under normal circumstances, a computer device may perform any of commands such as shut-down, specific programs suspended, and network connection interrupted due to security consideration. However, in some special cases, such as in response to the need for some services, a computer device may not be allowed to be powered off, and only specific programs or network is allowed to be suspended or interrupted. Through the aforementioned action list initiatively provided to the security management device, the security management device can immediately know actions the computer device is currently allowed to perform. 
         [0027]    It is another aspect of the present invention that the actions between the computer device and the security management device are communicated through generic action code. The naming and coding of the generic action code are common in all computer devices, and are not specific to a single or specific computer device, and even not limited to vendor-specific products. Each computer device can be managed and operated by mapping the generic action code to the corresponding action script containing action commands and parameters. Therefore, through the generic action code, the security management device no longer needs to know the specific details and command syntax of the computer device. 
         [0028]    It is a further aspect of the present invention that when the security management device issues a command to the computer device, it may come with a trigger condition for actions to be executed. This can be applied to the situation where the security management device determines that a security risk is elevated but not yet reached the degree of danger. The advantage of this approach is providing more immediate reaction. Since whether a condition is met can be determined by a computer device (or additional auxiliary device), upon determining that a condition is met, which can be viewed as a risk reaches a threshold, the computer device can perform the corresponding action immediately without reporting to the security management device. This not only increases the efficiency of reaction, but significantly reduces the load of the security management device. In particular, the loading of the security management device is a key factor that will affect the device&#39;s ability to fight against the attack when the attack occurs. 
         [0029]    Further, in consideration of reducing the load of the security management device, the present invention further provides a security management device which can issue a so-called “spread-style” or “chain reaction type” command and the corresponding trigger condition, so that the subsequent multiple computer devices can perform actions according to the condition preset by the security management device without the security management device involved, as described hereinafter. The security management device can issue a command to the second computer device (or even the third computer device) a command and the corresponding condition to the first computer device, and the first computer device (or other auxiliary device) will determine if the condition is met. Upon determining the condition is met, the first computer device can send a message to the second computer device to ask the second computer device to perform the action, or further ask the second computer device to send a message to a third computer device when another condition is met to ask the third computer device to perform the action. Accordingly, the chain-reaction effect can be achieved. Another approach lies in that the security management device can issue a target and the corresponding condition to the first computer device, and then the first computer device (or other auxiliary device) will determine if the condition is met. Upon determining that the trigger condition is met, the first computer device itself can determine a specific action performed by itself, and (or) send a message to the second computer device and (or) the third computer device to ask the second computer device and (or) the third computer device to perform the action to achieve the target the security management device is requesting. 
         [0030]    In addition to the computer device described above, the present invention further includes the aforementioned security management device, and provides a computer program product for the aforementioned computer device and security management device to use. 
         [0031]    Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
         [0032]    Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
         [0033]    The following description, the appended claims, and the embodiments of the present invention further illustrate the features and advantages of the present invention. 
         [0034]    Referring now to  FIG. 1  through  FIG. 3B , computer systems/devices, methods, and computer program products are illustrated as structural or functional block diagrams or process flowcharts according to various embodiments of the present invention. The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
         [0035]    &lt;System Architecture&gt; 
         [0036]      FIG. 1  illustrates hardware architecture of a computer system  100  according to an embodiment. The computer system  100  includes a security management device  102  and a computer device  104 . The security management device  102  is connected to the computer device  104  via a network (not shown); preferably but not limited thereto, the security management device  102  is connected to the computer device  104  via a local area network (LAN). It should be understood that  FIG. 1  only illustrates one computer device  104 , but this is only for the purpose of simplifying the illustration. The present invention can be extended to more than one of the computer devices  104 , and each computer device  104  is a homogeneous or a heterogeneous computer device. 
         [0037]    The computer device  104  may be a web server, an email server, a firewall device, or other network appliance which can be connected to an external network (not shown). Therefore, the computer device  104  directly faces security threats from the external network, such as Distributed Denial of Service (DDoS) attacks, but it may also be subject to security threats from the internal network, such as computer viruses. 
         [0038]    As shown in  FIG. 1 , the computer device  104  includes an application AP and a management program MP, and maintains a database DB. The application AP works to provide a major service for the computer device  104 . Taking a web server for example, the application AP provides web hosting service (referring to, for example, Apache HTTP Server or IBM HTTP Server applications). Also, in the process of the application AP working to provide services, the application AP will generate logs LG to record events occurred. 
         [0039]    The management program MP is preferably, but not limited thereto, executed as an operating systems (such as Linux), through the action as referred to herein, can manage hardware/software operations in the computer device  104 , such as power-on/off, turning on/off a specific communications port, and turning on/off a specific program or service. For details about the aforementioned, refer to the existing web servers, email servers, firewall devices, or other network appliances. 
         [0040]    The management program MP can know what management actions may be allowed to execute through monitoring the hardware/software operation of the computer device  104 . Further, the management program MP records the actions allowed to execute in the moment in the list LS and saves them in the database DB (which may be a module in the management program MP). Also, the management program MP can instantly update the actions recorded in the list LS according to the current hardware/software operation status of the computer device  104 , and provide the updated list LS to the security management device  102 . 
         [0041]    The action list LS and the logs LG generated by the aforementioned application AP can also be combined into a single message MSG 1  to be provided to the security management device  102 . However, it shall be understood that each of the action list LS and the logs LG can be provided to the security management device  102  respectively. In addition, as shown in  FIG. 1 , the computer device  104  includes an information transmission unit  106  for sending the logs LG and the list LS or other information to the security management device  102 . The information transmission unit  106  may be dedicated to transmitting information to the security management device  102 , but can also be used to send other information to another computer device on the web, but the present invention is not intended to be limited thereto. 
         [0042]    In a preferred embodiment (but not limited thereto), the management program MP records the action allowed to be executed in the moment with the generic action code. The generic action code may be a generic name or digit, but the naming or coding scheme is not specific to the computer device  104 . In other words, different computer devices  104  (e.g. a web server and a firewall device) can share the generic action code, such that the security management device  102  can communicate with all kinds of computer devices  104  through the generic action code. 
         [0043]    The following is an example of the list LS in XML format, where the id is a digit and the name is a brief explanatory text (e.g. the target or result to be achieved by this action), but both can be used together with other computer devices  104 . Also, in this example, the enabled value “true” or “false” is used to inform the security management device  102  whether this action is allowed to execute now. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;ActionPool&gt; 
               
               
                  &lt;Action id=“1” name=“restart system” enabled=“true”/&gt; 
               
               
                  &lt;Action id=“2” name=“restart service” enabled=“true”/&gt; 
               
               
                  &lt;Action id=“3” name=“shutdown service ” enabled=“false”/&gt; 
               
               
                 &lt;/ActionPool&gt; 
               
               
                   
               
             
          
         
       
     
         [0044]    On the other hand, as shown in  FIG. 1 , the security management device  102  includes an analysis unit  108  and a processing unit  110 . The analysis unit  108  performs a security analysis according to the logs LG provided by the computer device  104  (or data provided by other computer device) to generate intelligence. Refer to existing security management devices for this part. Further, the processing unit  110  selects a proper action from the list LS according to the intelligence acquired from the security analysis. For example, if the intelligence of the security management device  102  indicates that an abnormal event occurred in the computer device  104 , the processing unit  110  selects an action from the list LS in the aforementioned example, e.g. selects the action where the id is “2” and the name is “restart service”, and sends a message MSG 2  back to the computer device  104  to ask the computer device  104  to restart the application AP and see whether the abnormal event continues to occur. The following is an example of the message MSG 2  in XML format. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTP-8”?&gt; 
               
               
                  &lt;ActionToPerforms&gt; 
               
               
                   &lt;ActionToPerform actionId=“2” actionName=“restart service”/&gt; 
               
               
                  &lt;/ActionToPerforms&gt; 
               
               
                   
               
             
          
         
       
     
         [0045]    Furthermore, as shown in  FIG. 1 , the computer device  104  includes an information receiving unit  107  for receiving a message sent back by the security management device  102 . The information receiving unit  107  can be dedicated to receiving information to the security management device  102 , but can also be used to receive additional information to other computer devices on the web, but the present invention is not limited thereto. 
         [0046]    In this embodiment, since the message MSG 2  sent back from the security management device  102  employs the generic action code (actionId=“2” actionName=“restart service”) to record the action the processing unit  110  wants the computer device  104  to perform, the computer device  104  needs to acquire script and relevant details of the actions specified by the code according to the generic action code to correctly perform the action the security management device  102  is requesting. In this regard, the computer device  104  is provided with a mapping module  112  having a mapping table MT. The following is an example of the mapping table MT in XML format. The action code (e.g. actionId=“2”) in the message MSG 1  can be used to find out the corresponding path and parameter of the script (path=“/sbin/service” param=“httpd restart”/). 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;ActionMapping&gt; 
               
               
                  &lt;Command actionId=“1” path=“/usr/sbin/shutdown” param=“-r 
               
               
                 now”/&gt; 
               
               
                  &lt;Command actionId=“2” path=“/sbin/service”param=“httpd 
               
               
                 restart”/&gt; 
               
               
                  &lt;Command actionId=“3” path=“/sbin/service” param=“httpd stop”/&gt; 
               
               
                 &lt;/ActionMapping&gt; 
               
               
                   
               
             
          
         
       
     
         [0047]    In another embodiment, in accordance with the security intelligence obtained from security analysis, the processing unit  110  not only determines the action the computer device  104  is required to perform, but also sets a trigger condition for whether the computer device  104  needs to perform an action and sends them together back to the computer device  104  through a message MSG 3 . The following is an example of the message MSG 3  in XML format, where the trigger condition is the number of http links per second exceeds 300, and the memory resources used by the application AP (e.g. the Apache HTTP Server) exceeds 80% of total memory resources of the computer device  104 . If this condition is met, the action the computer device  104  needs to perform is to restart the application AP. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;Rule&gt; 
               
               
                  &lt;Conditions&gt; 
               
               
                    &lt;Operator name=“AND”&gt; 
               
               
                     &lt;Condition name=“http.connection” operator=“greater” value 
               
               
                 =“300”/&gt; 
               
               
                     &lt;Condition name=“http.memory” operator=“greater or 
               
               
                 equal” value =“80%”/&gt; 
               
               
                    &lt;/Operator&gt; 
               
               
                   &lt;/Conditions&gt; 
               
               
                  &lt;ActionToPerform actionId=“2” actionName=“restart service”/&gt; 
               
               
                 &lt;/Rule&gt; 
               
               
                   
               
             
          
         
       
     
         [0048]    It should be noted that in the embodiment described above, the computer device  104  may include a monitoring and control program MC (preferably used as a function module under the management program MP) for determining if the condition set by the processing unit  110  is met. However, whether the condition set by the security management device  102  is met may not necessarily be determined by the computer device  104  itself, but may be determined by the device other than the computer device  104 , which may then inform the computer device  104 . 
       Alternative Embodiment 1 
       [0049]      FIG. 2A  illustrates a hardware architecture of a computer system  200  according to an embodiment. The present embodiment is described in conjunction with a flowchart as shown in  FIG. 2B . The computer system  200  includes a security management device  202  and computer devices  204 ,  214 . The basic illustration of the security management device  202  and the computer device  204 ,  214  can be found in  FIG. 1 , and will not be described in detail herein. However, it should be noted that the computer devices  204 ,  214  in the embodiment in  FIG. 2  are homogeneous computer devices and together provide an information service. For example, the computer devices  204  and  214  belong to a web server cluster. However, it should be understood that the web server cluster may contain more computer devices (not shown). 
         [0050]    In this cluster, the computer device  204  is served as a Master node, and the computer device  214  and the other computer device in the cluster (not shown) are served as Slave nodes. The computer device  204  served as a Master node can know the operation status of the other Slave node, and thus it is more suitable for the computer device  204  to provide the list LS to the security management device  202  on behalf of the entire cluster (Step  20 ). Therefore, in this embodiment, the list LS can record an action the cluster-level can perform (e.g. the entire cluster to stop web hosting services) or a management target the cluster-level can achieve (e.g. adjusting the service rate of the entire cluster or http MaxClients allowed to build per second to a specific value). Also, the security management device  202  can select an appropriate action or management target from the list LS according to security analysis and sends it with the message MSG 4  back to the computer device  204  served as a cluster Master node (Step  22 ). The management program MP in the computer device  204  then determines actions each of the computer device  204  and the computer device  214  needs to perform through a predetermined algorithm or an existing coordination management mechanism within the cluster, and informs the computer device  214  through the message MSG 5  (Step  24 ). As to the cluster within the predetermined algorithm or existing coordination and management mechanism, refer to an existing server cluster approach. This will not be described in detail herein. 
         [0051]    In a preferred embodiment, but not limited thereto, in addition to determining the appropriate cluster-level action or management target, the security management device  202  can also set a trigger condition and send it back to the computer device  204  through the message MSG 4  (Step  22 ). The following is an example of the message MSG 4  in XML format, where the trigger condition is the number of http links of the entire cluster per second exceeds 1,000,000, and the source IP address of http links is “10.3.4.5”. If this condition is met, the server cluster needs to reach the entire cluster service ratio to 50% or higher. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;Rule&gt; 
               
               
                  &lt;Conditions&gt; 
               
               
                   &lt;Operator name=“AND”&gt; 
               
               
                    &lt;Condition name=“cluster.http.connection.sec” 
               
               
                 operator=“greater” value=“1000000”/&gt; 
               
               
                    &lt;Condition name=“src.ip” operator=“equal” 
               
               
                 value=“10.3.4.5”/&gt; 
               
               
                   &lt;/Operator&gt; 
               
               
                  &lt;/Conditions&gt; 
               
               
                  &lt;ActionToPerform actionName= “maintain cluster service rate at 50% 
               
               
                 or above”/&gt; 
               
               
                 &lt;/Rule&gt; 
               
               
                   
               
             
          
         
       
     
         [0052]    It should be noted that the computer device  204  in the aforementioned embodiment may include a monitoring and control program MC (preferably served as a function module under the management program MP), for determining if a condition set by the security management device  202  is met. In general, when served as a Master node, the monitoring and control program MC of the computer device  204  can obtain information returned by the other Slave node to know the operation status of each Slave node. Therefore, it should be more convenient to use the computer device  204  to determine if a cluster-level trigger condition is met. However, it should be understood that the present invention is not intended to be limited thereto. 
       Alternative Embodiment 2 
       [0053]      FIG. 3A  illustrates a hardware architecture of a computer system  300  according to an embodiment which will be described in conjunction with a flowchart as shown in  FIG. 3B . The computer system  300  includes a security management device  302  and computer devices  304 ,  314 , and  324 . The basic illustration of the security management device  302  and the computer devices  304 ,  314 , and  324  can be found in  FIG. 1  and  FIG. 2A , and will not be described in detail herein. However, it should be noted that different from  FIG. 2A , the computer devices  304 ,  314 , and  324  in the embodiment as shown in  FIG. 3A  are heterogeneous computer devices providing different services respectively. For example, the computer device  304  is a web server, the computer device  314  is a firewall device, and the computer device  324  is an intrusion detection system (IDS). However, it should be understood that the computer system  300  may include more different types of computer devices (not shown). 
         [0054]    Hereinafter, a hypothetical situation is used to illustrate the present embodiment. The computer device  324  is served as an intrusion detection system (IDS) to detect a suspected but not confirmed DDoS network attack, and informs the security management device  302  with a message MSG 6  (Step  30 ). Refer to the prior art for the relevant description. This will not be described in detail herein. In general, a DDoS network attack target is the computer device  304  which is served as a web server. Thus, the security management device  302  sends a message MSG 7  to the computer device  304  to issue a so-called “spread-style” or “chain reaction type” action command and the corresponding trigger condition (Step  31 ). Thereby the computer device  304  (web server), the computer device  314  (firewall), and the computer device  324  (intrusion detection system (IDS) can coordinate with each other to cope with possible DDoS network attacks without further intervention by the security management device  302 . Also, it should be noted that in this embodiment the computer device  304  may be similar to the computer device  204  as shown in  FIG. 2A  to be a server cluster Master node. 
         [0055]    The following is an example of the message MSG 7  in XML format where a first trigger condition set by the security management device  302  is that the number of http links of the computer device  304  (web server) per second exceeds 1,000,000, and the source IP address of http link is “10.3.4.5”. If the computer device  304  (or other auxiliary devices) determines that the condition is met (Step  32 ), the management program MP of the computer device  304  needs to perform the following actions. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 &lt;?xml version=“1.0” encoding=“UTF-8”?&gt; 
               
               
                 &lt;Rule&gt; 
               
               
                  &lt;Conditions&gt; 
               
               
                   &lt;Operator name=“AND”&gt; 
               
               
                    &lt;Condition name=“http.connection.sec” operator=“greater” 
               
               
                 value=“1000000”/&gt; 
               
               
                    &lt;Condition name=“src.ip” operator=“equal” 
               
               
                 value=“10.3.4.5”/&gt; 
               
               
                   &lt;/Operator&gt; 
               
               
                  &lt;/Conditions&gt; 
               
               
                  &lt;ActionToPerform actionName=“stop web service”/&gt; 
               
               
                  &lt;ActionToPropagate&gt; 
               
               
                   &lt;ActionTarget id=“Firewall” ip=“1.2.3.4”&gt; 
               
               
                    &lt;Rule&gt; 
               
               
                     &lt;Conditions&gt; 
               
               
                      &lt;Condition name=“src.ip” operator=“equal” 
               
               
                 value=“10.3.4.5”/&gt; 
               
               
                     &lt;/Conditions&gt; 
               
               
                     &lt;ActionToPerform actionName=“block source ip 
               
               
                 traffic”/&gt; 
               
               
                    &lt;/Rule&gt; 
               
               
                   &lt;/ActionTarget&gt; 
               
               
                   &lt;ActionTarget id=“IDS” ip=“1.2.3.6”&gt; 
               
               
                    &lt;Rule&gt; 
               
               
                     &lt;Conditions&gt; 
               
               
                      &lt;Condition name=“src.ip” operator=“equal” 
               
               
                 value=“10.3.4.5”/&gt; 
               
               
                     &lt;/Conditions&gt; 
               
               
                     &lt;ActionToPerform actionName=“block source ip 
               
               
                 traffic”/&gt; 
               
               
                     &lt;ActionToPropagate&gt; 
               
               
                      &lt;ActionTarget id=“WebServer_01” ip=“1.2.6.8”&gt; 
               
               
                       &lt;Rule&gt; 
               
               
                        &lt;ActionToPerform actionName=“restart 
               
               
                 web service”/&gt; 
               
               
                       &lt;/Rule&gt; 
               
               
                      &lt;/ActionTarget&gt; 
               
               
                     &lt;/ActionToPropagate&gt; 
               
               
                    &lt;/Rule&gt; 
               
               
                   &lt;/ActionTarget&gt; 
               
               
                  &lt;/ActionToPropagate&gt; 
               
               
                 &lt;/Rule&gt; 
               
               
                   
               
             
          
         
       
     
         [0056]    First, the management program MP of the computer device  304  stops web hosting service (which is equivalent to stopping the application AP of computer device  104  as shown in  FIG. 1 ). In the meantime, in response to said first trigger condition is met, the management program MP of the computer device  304  sends or distributes actions and trigger conditions specified by the security management device  302  with the message MSG 8  and the message MSG 9  to the computer device  314  and the computer device  324  respectively according to the network address of other computer devices (e.g. the computer device  314  and the computer device  324 ) specified by the security management device  302  in the message MSG 7  (Step  33 ). For the message communication between the computer device  314  and the computer device  324 , refer to the message communication between the security management device  302  and the computer device  304 . 
         [0057]    With further reference to the aforementioned example of the message MSG 7  in XML format, for the computer device  314  (a firewall device), the trigger condition set by the security management device  302  in the message MSG 7  is that if the source IP address of http links is “10.3.4.5”, the computer device  314  determines that the condition is met, and the management program MP of the computer device  314  blocks the IP address of the network communications. 
         [0058]    On the other hand, for the computer device  324  (intrusion detection system (IDS)), the trigger condition set by the security management device  302  in the message MSG 7  is the same as the one provided to the computer device  314 , i.e. if the source IP address is “10.3.4.5”, and the computer device  324  determines that the condition is met (Step  34 ), the management program MP of the computer device  324  first blocks network communication of the IP address. In addition, the management program MP of the computer device  324  further sends or distributes the action specified by the security management device  302  to the next computer device with message MSG 10  according to the IP address of the next computer device specified by the security management device  302  in the message MSG 7  (Step  35 ). 
         [0059]    In this embodiment, the computer device following the computer device  324  specified by the security management device  302  in the message MSG 7  is just the computer device  304 , and the action requiring the management program MP of the computer device  304  to perform is restart a web hosting service. However, it should be obvious that the present invention is not limited thereto. Any computer device in the computer system  300  other than the computer device  324  may be used as the next computer device of the computer device  324 . In addition, while the security management device  302  only sets the action required to perform for the computer device following the computer device  324  (the computer device  304  in this example) in the message MSG 7  and does not add a trigger condition, it should be understood that in other embodiments, a trigger condition can be added to the action the next computer device is required to perform. 
         [0060]    Furthermore, it should be noted that in the example described above, the computer devices  304 ,  314 , and  324  may all include a monitoring and control program MC (preferably served as function modules under the management program MP) for determining if a trigger condition set by the security management device  302  is met. The monitoring and control program MC of the computer devices  304 ,  314 , and  324  can further communicate with other computer devices to monitor the operation status of other computer devices and determines if a trigger condition set by the security management device  302  is met. However, it should be understood that whether the aforementioned trigger condition is met may not necessarily be determined by the computer devices  304 ,  314 , and  324  themselves, but may be determined by some other auxiliary devices. 
         [0061]    The present invention can be embodied in any other specific manners without departing from the spirit or essential features of the present invention. Every aspect of the aforesaid embodiments of the present invention must be deemed illustrative rather than restrictive of the present invention. Hence, the scope of the present invention is defined by the appended claims instead of the above description. All equivalent meanings and scope which fall within the appended claims must be deemed falling within the scope of the appended claims.