In the prior art, patent CN 201610330336.3 proposes a defense system, which includes a transparent firewall, a timing inspection module, a flow statistics module, a virus isolation module, a virus feature matching module, a port audit module, a flow statistics module, a network anomaly evaluation module, a defense decision generation module, a defense decision execution module, an emergency channel module, a restoration module, and a data isolation uploading module. The monitoring and auditing of the network flow are realized, and the good state of the network is maintained; the network immunity is improved by analyzing and memorizing unknown invasion behaviors; after the intrusion, the damage range can be effectively controlled, the smooth network and the normal service provision are ensured, meanwhile, different defense decision schemes can be automatically generated and executed according to different network attacks, the autonomous repair and restoration capability of the system is improved, and the stable operation of the network is maintained. However, the invention does not quantify the defense system, and only establishes the defense strategy.
Patent CN 201810588918.0 proposes "network target defense effectiveness evaluation method, electronic device, storage medium and system", and specifically discloses a network target defense effectiveness evaluation method, which includes performing hierarchical processing on a network resource map to obtain a hierarchical network resource map; acquiring an initial hierarchical network resource map at an initial moment and a current hierarchical network resource map; detecting the similarity between the initial node layer and the current node layer; calculating the resource dependency relationship and the resource association degree of the resource layers in the initial hierarchical network resource graph and the current hierarchical network resource graph; calculating the defense success rate and the defense cost of the current hierarchical network resource graph according to the resource association degree and the resource dependency relationship; and evaluating the defense benefits according to the defense success rate and the defense cost.
Patent CN 201810594501.5 proposes "attack-oriented network security situation prediction method, device and system", and specifically discloses an attack-oriented network security situation prediction method, device and system, the method includes: detecting and collecting alarm data and network environment operation and maintenance information under a network countermeasure environment, and acquiring an element set required by network security situation prediction, wherein the element set comprises three types of information of an attacker, a defender and a network environment; evaluating the ability of an attacking party and the level of a defending party, establishing a dynamic Bayesian attack graph, and calculating the number of attack stages and the occurrence probability vector of an attack state; and quantifying the network security situation value from the space-time dimension by combining the vulnerability scoring standard and the network asset information. The invention mainly aims at predicting the network security situation, so as to provide a defense construction place guide, but does not relate to the efficiency evaluation of a network defense system.
Patent CN 201811358905.0 proposes "network security performance evaluation method based on attack and defense correlation matrix", and specifically discloses a network security performance evaluation method based on attack and defense correlation matrix, belonging to the technical field of information security. The method comprehensively considers the system defense capability, the influence on the system performance, the core asset performance and the protection capability after the network is attacked, the service provided by the system and the like, and realizes the evaluation on the network security efficiency by calculating the attack and defense incidence matrix and integrating the weight accumulation of a plurality of discrete points by using the change values of the target network before and after the attack. The invention can evaluate the defense capacity of a single equipment node, and is still deficient in defense quantification of the whole network system.
Patent CN 201911028421.4 proposes "a method, an apparatus, an electronic device and a storage medium for evaluating the current status of a network environment", in which a method, an apparatus, an electronic device and a storage medium for evaluating the current status of a network environment are specifically disclosed, so as to solve the problems of low evaluation accuracy and high cost in the prior art that a method of penetration testing and virtual environment construction is mostly adopted to evaluate the current status of network security. The method comprises the following steps: researching the target network environment information, performing resource allocation according to the information, and establishing a simulation network environment of the target network environment; utilizing a simulation intrusion scheme to intrude the simulation network environment, describing an intrusion process and a protection condition, generating an intrusion result, and visually displaying the intrusion process, the protection condition and the intrusion result; deducing and generating an electronic report according to the intrusion process, the protection condition and the intrusion result; and the evaluators evaluate the defense condition of the target network according to the electronic report and the visual display condition, and generate a target network environment current state evaluation report and a target network environment optimization suggestion report. But this invention does not quantify the assessment of defense efficacy.
Disclosure of Invention
The invention aims to solve the technical problem of providing a defense efficiency evaluation method applied to a network shooting range, which starts with the severity of potential threat risk and two dimensions of response actions of equipment with a defense function during attack defense, evaluates the design defects of a defense system and the problems existing in the actual operation of the equipment, quantifies the defense effect and realizes the objective evaluation of the defense efficiency.
The invention adopts the following technical scheme for solving the technical problems: the invention designs a defense efficiency evaluation method applied to a network shooting range, which comprises a detection method of the defense efficiency of the network shooting range and comprises the following steps:
step A, defining a preset time length range from the initial state moment of the network target range as a detection time period, and counting, for each mirror image device in the network target range, the complete threat paths of the mirror image device from the initial state to the final state sequentially passing through each potential threat in the detection time period as follows:
Pn={sn1、en1、sn2、…、enm-1、snm、…enM-1、snM}
where N is e {1, …, N }, where N represents the total number of mirrored devices in the network range, sn1Representing the initial state of the nth mirror device in the network target range, wherein M belongs to {1, …, M }, and M represents the total state number of the mirror device in the detection time period; e.g. of the typenm-1 represents the m-1 th potential threat passed by the nth mirroring device, snmRepresents the state of the nth mirror device after the (m-1) th potential threat, snMRepresents the state of the nth mirror device after the M-1 th potential threat, i.e. the last state of the mirror device in the detection time period, PnRepresenting that the nth mirror image equipment sequentially passes through all potential threats and a complete threat path from an initial state to a final state in a detection time period, and then entering a step B;
and B, aiming at each mirror image device in the network target range, according to the complete threat path of the mirror image device, according to the following formula:
obtaining the probability of each image device being successfully attackedWherein j is more than 1 and less than or equal to k is more than or equal to i and less than or equal to M, ankRepresenting the probability of successful transition from the kth state to the next state of the nth mirroring device within the detection time period, bnkIndicating the probability that the nth mirroring device has not successfully transitioned from the kth state to the next state during the detection period, PntRepresenting the probability of successful attack of the nth mirror image equipment, and then entering the step C;
step C, according to the probability that each mirror image device is successfully attacked correspondingly, obtaining the risk level of each different type of potential threat related in the complete threat path of each mirror image device, and then entering step D;
step D, aiming at each mirror image device in the network target range, obtaining each different type of potential threat passed by the mirror image device in the complete threat path, and obtaining the defense result of the mirror image device aiming at each different type of potential threat under the successful attack probability of the mirror image device according to the complete threat path of the mirror image device; then entering step E;
step E, according to the following formula:
obtaining a defense performance result S of the network shooting range, wherein w
nWeight of the nth mirror device in the network range, l
n∈{1、…、L
n},L
nRepresenting the number of different types of potential threats in the complete threat path of the nth mirror device, l
nRepresenting the ith type of potential threat in the nth mirrored device's full threat path,
indicates the probability P that the nth mirror device is successfully attacked at
ntNext, as a result of the defense against the ith type of potential threat in its complete threat path,
representing the nth mirror device in the complete threat pathRisk levels for l types of potential threats.
As a preferred technical solution of the present invention, the step C includes the steps of:
c1, aiming at each mirror image device in the network target range, sequencing the mirror image devices in the sequence of the successful attack probability from small to large to form mirror image device sequencing, and then entering the step C2;
step C2., normalizing the successful attack probability of each mirror image device in the network target range to obtain each normalization result, then taking each normalization result as the coefficient of each mirror image device in the mirror image device sequence from big to small in sequence, and entering step C3;
step C3., aiming at each different type of potential threats involved in the complete threat path of all the mirror image devices, the potential threats attack each mirror image device in the network target range respectively, and the sum of the coefficients of each successfully attacked mirror image device is obtained as the risk result value corresponding to the potential threat; further acquiring risk result values corresponding to the potential threats respectively, and then entering step C4;
and C4, aiming at each potential threat, sequencing the potential threats in the order of the risk result values corresponding to the potential threats from small to large, and forming the risk level of each potential threat according to the sequencing serial number of each potential threat from 1.
As a preferred technical scheme of the invention: and D, according to successful attack, marking the defense result as 1, and if unsuccessful attack, marking the defense result as 0, and according to the complete threat path of the mirror image equipment, obtaining the defense results of the mirror image equipment aiming at the different types of potential threats respectively under the probability that the mirror image equipment is successfully attacked.
As a preferred technical scheme of the invention: and E, performing normalization operation aiming at the preset economic value of each mirror image device in the network target range, wherein each result is the weight of each mirror image device.
As a preferred technical scheme of the invention: the method for detecting the importance of the mirror image equipment is used for realizing the detection of the importance value of the target mirror image equipment and comprises the following steps:
step i, determining each mirror image device in the defense range corresponding to the target mirror image device to form a defense mirror image device set corresponding to the target mirror image device, and then entering step ii;
and ii, taking the defense mirror image device set corresponding to the target mirror image device as a network target range, and executing the methods from the step A to the step E to obtain a defense efficiency result of the network target range, namely, the defense efficiency result is taken as an importance value of the target mirror image device.
As a preferred technical scheme of the invention: the method also comprises a mirror image equipment deployment importance detection method used for obtaining the quantitative detection of the mirror image equipment deployment importance in the network target range, wherein the mirror image equipment deployment importance detection method is based on the execution of the steps A to C and also comprises the following steps I to IV;
step I, aiming at each mirror image device in a network target range, respectively, obtaining a response result quantized value of the mirror image device to each different type of potential threats in the complete threat path based on the complete threat path of the mirror image device, and then entering step II;
step II, respectively aiming at each mirror image device in the network target range and response result quantized values of the mirror image device to different types of potential threats in the complete threat path, executing normalization operation to obtain each normalization result and form influence weights respectively corresponding to each response result quantized value; then entering step III;
step III, aiming at each mirror image device in the network target range, respectively, according to the following formula:
obtaining the defense effect corresponding to each mirror image device in the network shooting range; in the formula (I), the compound is shown in the specification,
representing the response result of the nth mirror device to the ith type potential threat in the complete threat pathThe value of the quantization is then calculated,
representing the influence weight of the response result quantized value of the ith type potential threat in the nth mirror device to the ith type potential threat in the complete threat path,
representing the defense effect corresponding to the nth mirror image equipment in the network target range; then entering step IV;
step iv. according to the following formula:
quantitative detection result I for obtaining deployment importance of mirror image equipment in network target rangedq。
Compared with the prior art, the defense effectiveness evaluation method applied to the network target range has the following technical effects by adopting the technical scheme:
the defense effectiveness evaluation method applied to the network shooting range starts with the severity of potential threat risk and two dimensions of response actions of equipment with defense function during attack defense, realizes evaluation aiming at design defects of a defense system and problems existing in actual operation of the equipment, quantifies defense effect, realizes objective evaluation of defense effectiveness, can meet defense scheme effectiveness evaluation under different application scenes and safety risk definition standards in application, does not need to perform independent modeling analysis on each specific scene, can perform effectiveness evaluation on defense strategies of the system in a quantified mode, and is more comprehensive and controllable compared with a method for simulating network attack behaviors by security personnel by penetration test, and is favorable for determining the relationship between network security equipment and protected assets, The relationship between the security threat and the defense, and the relationship between the security device and the overall defense system, achieve objective assessment of defense effectiveness.
Detailed Description
The following description will explain embodiments of the present invention in further detail with reference to the accompanying drawings.
The network target site is composed of a plurality of mirror image devices which are connected with each other, and each mirror image device provides functional services to other mirror image devices through a network, as shown in fig. 1, the mirror image devices in the network target site are carriers of a series of data sets, and users access the functional services of the devices in the system through the network.
For each mirrored device in the network range, with the set Data ═ Data1,data2,...,datanIndicates all data contained on a mirrored device.
The mirroring device provides its interface to interact with the outside through the functional services provided by Service, and one mirroring device may contain several functional services. Each service is represented by S, and Data is used for the collection of Data used and influenced by S at runtime
SIs shown, and
defining a service provided by the mirroring device and Data affected by the service as State { S, Data }S}。
The operation authority of data can be divided into read authority and write authority, and the matrix per ═ r, w is used]TIndicating the rights to a certain data, r the read rights and w the write rights. For S in State, its DataSIs the permission matrix per ═ per [ per ]d1,perd2,...,perdn]. For the permission matrix per1And per2Assuming the matrix dimensions are the same, aijRepresentative matrix per1Element of ith row and jth column, bijRepresentative matrix per2Row i and column j elements, pairAt any of i and j, has aij≤bijThen per1≤per2Is to represent per1Is not greater than per2The right of (1).
For a service S in the State, the authority of a User with different identities to access the service S is per (User), and one service S may provide services to a plurality of User roles. Then the right to S run in State is denoted perStateIf the average value of per is less than or equal to perState。
The potential threat is an inherent property existing in the whole life cycle of the mirroring device, and is any factor which can potentially cause a security problem to the network system. A network attack is any act of attempting to expose, destroy, modify, crash, illegally access or otherwise use target data on a target network and system. The potential threat may or may not occur. The vulnerability is a known potential threat point on the mirror image equipment, the attack is promoted to be successful by utilizing the vulnerability, and the essence is that an attacker utilizes the vulnerability to launch the attack so that the authority of the attacker is changed.
The potential threat presented by each mirrored device may be denoted ATT ═ ATT1,att2,...,attn}。
The security hole existing in each mirroring device can be expressed as VUL ═ { VUL ═ VUL1,vul2,...,vuln}。
If an attacker attacks a certain image device, the attack flow can be represented as (srcip, srcport, destip, destport, pro, att), where att represents the potential threat type corresponding to the attack.
If a bug vul exists in the service S provided on a certain image device, and an attacker operates with the User identity User, the authority of the attacker is per (User). After the attacker successfully utilizes the vulnerability, the authority is changed from per (User) to per '(User), namely, the vulnerability vul realizes the conversion from per (User) to per' (User). Generally per (User) ≦ per' (User), i.e., the attacker gains higher rights to the operation of the mirroring device by exploiting vulnerabilities.
Various mirror image devices with security defense functions are deployed in a network system to form a security defense system, so that threats existing in the mirror image devices in the network system can be defended.
Depending on the type of function, the system defense can be divided into four aspects, detection, blocking, authentication, and encryption security. The detection class can find out the attack behavior to the system, but can not prevent the attack behavior; blocking classes can prevent aggressive behavior; the encryption security can encrypt the data, and the data has unreadable authority to unauthorized users; authentication is used for authenticating a user, and the user obtains corresponding authority.
Different defense functions are expressed using Fun.
For attack streams (srcip, srcport, destip, destport, pro, att), if att ∈ Fun, it means that the mirroring device can defend against the potential threat att.
Use (detect, stop, war, log) to represent responses to attacks, where detect represents detection, stop represents blocking, war represents alarm, and log represents detailed records of heap attacks.
The type indicates the access mode of the device with the defense function in the whole range system, and when the type is 1, the serial access is indicated, and when the type is 0, the bypass access is indicated.
For attack flows (srcip, srcport, destip, destport, pro, att), only devices that deploy defense functions can defend against the attack
Based on the modeling of the network target range, the invention designs a defense effectiveness evaluation method applied to the network target range, which comprises a detection method of the defense effectiveness of the network target range, and specifically executes the following steps A to E as shown in fig. 2.
Step A, defining a preset time length range from the initial state moment of the network target range as a detection time period, and counting, for each mirror image device in the network target range, the complete threat paths of the mirror image device from the initial state to the final state sequentially passing through each potential threat in the detection time period as follows:
Pn={sn1、en1、sn2、…、enm-1、snm、…enM-1、snM}
where N is e {1, …, N }, where N represents the total number of mirrored devices in the network range, sn1Representing the initial state of the nth mirror device in the network target range, wherein M belongs to {1, …, M }, and M represents the total state number of the mirror device in the detection time period; e.g. of the typenm-1Represents the m-1 th potential threat, s, passed by the nth mirror devicenmRepresents the state of the nth mirror device after the (m-1) th potential threat, snMRepresents the state of the nth mirror device after the M-1 th potential threat, i.e. the last state of the mirror device in the detection time period, PnAnd the nth mirror image device sequentially passes through the complete threat path from the initial state to the final state of each potential threat in the detection time period, and then enters the step B.
And B, aiming at each mirror image device in the network target range, according to the complete threat path of the mirror image device, according to the following formula:
obtaining the probability of each mirror image device being successfully attacked, wherein j is more than 1 and less than or equal to k is more than or equal to i and less than or equal to M, ankRepresenting the probability of successful transition from the kth state to the next state of the nth mirroring device within the detection time period, bnkIndicating the probability that the nth mirroring device has not successfully transitioned from the kth state to the next state during the detection period, PntIndicating the probability of successful attack of the nth mirror device and then proceeds to step C.
And C, according to the probability of successful attack corresponding to each mirror image device, obtaining the risk level of each different type of potential threat involved in the complete threat path of each mirror image device, and then entering the step D.
In practical applications, the step C is performed as the following steps C1 to C4.
And C1, aiming at each mirror image device in the network target range, sequencing the mirror image devices in the sequence of the successful attack probability from small to large to form mirror image device sequencing, and then entering the step C2.
Step C2. is to perform normalization operation on the successful attack probability of each mirror image device in the network target range to obtain each normalization result, and then to take each normalization result as the coefficient of each mirror image device in the mirror image device sequence from large to small, and to proceed to step C3.
Step C3., aiming at each different type of potential threats involved in the complete threat path of all the mirror image devices, the potential threats attack each mirror image device in the network target range respectively, and the sum of the coefficients of each successfully attacked mirror image device is obtained as the risk result value corresponding to the potential threat; and obtaining a risk result value corresponding to each potential threat, and then entering step C4.
And C4, aiming at each potential threat, sequencing the potential threats in the order of the risk result values corresponding to the potential threats from small to large, and forming the risk level of each potential threat according to the sequencing serial number of each potential threat from 1.
Step D, aiming at each mirror image device in the network target range, obtaining each different type of potential threat passed by the mirror image device in the complete threat path, and obtaining the defense result of the mirror image device aiming at each different type of potential threat under the successful attack probability of the mirror image device according to the complete threat path of the mirror image device; then step E is entered.
In practical application, for the acquisition of the defense result, according to successful attack, the defense result is marked as 1, and if the attack is unsuccessful, the defense result is marked as 0, and according to the complete threat path of the mirror image equipment, the defense results of the mirror image equipment aiming at different types of potential threats respectively under the probability that the mirror image equipment is successfully attacked are acquired.
Step E, according to the following formula:
obtaining a defense performance result S of the network shooting range, wherein w
nRepresenting network targetsWeight of the nth mirror device in the field, l
n∈{1、…、L
n},L
nRepresenting the number of different types of potential threats in the complete threat path of the nth mirror device, l
nRepresenting the ith type of potential threat in the nth mirrored device's full threat path,
indicates the probability P that the nth mirror device is successfully attacked at
ntNext, as a result of the defense against the ith type of potential threat in its complete threat path,
representing the risk level of the ith type of potential threat in the nth mirror device's full threat path.
In application, if
It indicates that the defense system lacks the standard which can be achieved by the defense range in design, and safety workers need to deploy equipment with defense function at proper positions in a network system, so that by analyzing the defense result and the retrograde of each equipment in the network target range, a short board of the whole network safety defense system can be obtained, and the safety workers can be helped to perfect the defense system.
Regarding the weight of each mirror image device in the step E, in practical applications, a normalization operation is performed on the preset economic value of each mirror image device in the network target range, and each obtained result is the weight of each mirror image device.
Based on the defense performance evaluation method applied to the network target range, in practical application, the invention further designs a mirror image equipment importance detection method for realizing the detection of the importance value of the target mirror image equipment, and specifically executes the following steps i to ii.
And i, determining each mirror image device in the defense range corresponding to the target mirror image device to form a defense mirror image device set corresponding to the target mirror image device, and entering the step ii.
And ii, taking the defense mirror image device set corresponding to the target mirror image device as a network target range, and executing the methods from the step A to the step E to obtain a defense efficiency result of the network target range, namely, the defense efficiency result is taken as an importance value of the target mirror image device.
In addition, in practical application, the invention further designs a mirror image device deployment importance detection method for obtaining quantitative detection of mirror image device deployment importance in a network target range, wherein the mirror image device deployment importance detection method is based on the execution of the steps A to C and further comprises the execution of the following steps I to IV.
And step I, aiming at each mirror image device in the network target range, respectively, obtaining a response result quantized value of the mirror image device to each different type of potential threats in the complete threat path based on the complete threat path of the mirror image device, and then entering step II.
Step II, respectively aiming at each mirror image device in the network target range and response result quantized values of the mirror image device to different types of potential threats in the complete threat path, executing normalization operation to obtain each normalization result and form influence weights respectively corresponding to each response result quantized value; then step III is entered.
Step III, aiming at each mirror image device in the network target range, respectively, according to the following formula:
obtaining the defense effect corresponding to each mirror image device in the network shooting range; in the formula (I), the compound is shown in the specification,
representing the quantitative value of the response result of the nth mirror device to the ith type of potential threat in the complete threat path,
means for representing the response node of the nth mirror device to the ith type of potential threat in its complete threat pathThe weight of the impact of the quantitative value is affected,
representing the defense effect corresponding to the nth mirror image equipment in the network target range; then step IV is entered.
Step iv. according to the following formula:
quantitative detection result I for obtaining deployment importance of mirror image equipment in network target rangedq。
In application, the importance value of each mirror image device in the network target range and the quantitative detection result I of the deployment importance of the mirror image devices in the network target range are obtaineddqLater, for each mirror device value, a larger value represents a higher degree of importance of the mirror device in the defense system. If the combination of the mirror image devices in the respective defense ranges of the two mirror image devices is the same, the severity of the potential threat to be defended and the corresponding risk of the potential threat are also the same, when the importance value of the mirror image device is larger, the larger the threat types that the mirror image device can defend are, if the two mirror image devices can defend the threats faced by the mirror image devices in the defense ranges of the two mirror image devices, the defense effect value of the single mirror image device is 1, and when the importance value or the I of the mirror image device is the samedqThe larger the value, the higher the total economic value of the asset corresponding to the protection of the safety equipment.
The defense effectiveness evaluation method applied to the network shooting range is designed based on the severity of potential threat risk and two dimensions of response two actions of equipment with defense function during attack defense, realizes evaluation aiming at design defects of a defense system and problems existing in actual operation of the equipment, quantifies defense effect, realizes objective evaluation of defense effectiveness, can meet defense effectiveness evaluation under different application scenes and safety risk definition standards in application, does not need to perform independent modeling analysis on each specific scene, can perform effectiveness evaluation on defense strategies of the system in a quantified mode, and is more comprehensive and controllable compared with a method for simulating network attack behaviors by security personnel by penetration test, and is favorable for determining the relationship between network security equipment and protected assets, The relationship between the security threat and the defense, and the relationship between the security device and the overall defense system, achieve objective assessment of defense effectiveness.
The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.