CN111488556A - Nested document extraction method and device, electronic equipment and storage medium - Google Patents

Abstract

The application discloses a nested document extraction method, a nested document extraction device, an electronic device and a computer readable storage medium, wherein the method comprises the following steps: acquiring a target document to be extracted, and reading a document directory corresponding to the target document; extracting all sub-documents nested in the target document from the document directory; and respectively identifying the document content of each subdocument to identify whether confidential information exists in the subdocument. According to the method and the device, all the sub-documents nested in the target document can be extracted based on the document directory of the target document to be extracted, so that the extraction of the nested document is realized, the content of the sub-document is identified, whether confidential information exists in the sub-documents is determined, and information leakage can be effectively avoided.

Description

A nested document extraction method, device, electronic device and storage medium

technical field

The present application relates to the field of computer technology, and more particularly, to a nested document extraction method and apparatus, an electronic device, and a computer-readable storage medium.

Background technique

Nested documents, that is, documents added by inserting attachment objects in office documents such as office documents and RTF documents. DLP (Data leakage prevention) refers to a system for preventing leakage. The need to extract document content is common in current leaked DLP products, and most DLP products for document extraction only support the extraction of the current document content, but not nested documents, or even the extraction of multi-level nested document content. Therefore, It may lead to the leakage of confidential information if the user embeds the confidential information file into the document, and the leakage system cannot analyze the confidential information file. Therefore, how to solve the above problems is the focus of those skilled in the art.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a nested document extraction method and apparatus, an electronic device and a computer-readable storage medium, which can realize the extraction of nested documents, thereby effectively avoiding information leakage.

To achieve the above purpose, the present application provides a nested document extraction method, including:

Obtain the target document to be extracted, and read the document directory corresponding to the target document;

extracting all subdocuments nested in the target document from the document directory;

The document content of each sub-document is respectively identified to identify whether confidential information exists in the sub-document.

Optionally, after obtaining the target document to be extracted, the method further includes:

determining the document type corresponding to the target document;

The reading of the document directory corresponding to the target document includes:

The document directory corresponding to the target document is read according to the document type.

Optionally, the reading of the document directory corresponding to the target document according to the document type includes:

If the document type is the document type of the first type of version format, then read the composite document directory corresponding to the target document; the first type of version format includes any one of doc format, xls format, and ppt format;

If the document type is a document type of the second type of version format, the target document is decompressed, and after decompression, the multi-level document directory corresponding to the target document is read; the second type of version format includes docx Format, xlsx format, or pptx format.

Optionally, extract all subdocuments nested in the target document from the document directory, including:

By reading all folders of preset files in the compound document directory, all subdocuments nested in the target document are extracted.

Optionally, extract all subdocuments nested in the target document from the document directory, including:

reading a preset subdirectory under the multi-level document directory corresponding to the target document;

Extract all sub-documents stored in the preset sub-directory.

Optionally, before identifying the document content of each subdocument, the method further includes:

Determine whether the sub-document is a single document or a nested document;

If the subdocument is a nested document, the subdocument is used as the target document, and the step of extracting all subdocuments nested in the target document from the document directory is performed to perform iterative extraction.

Optionally, identifying the document content of each sub-document respectively includes:

If the sub-document is a single document, content extraction and identification of the sub-document are directly performed according to the document format corresponding to the sub-document.

To achieve the above purpose, the present application provides a nested document extraction device, comprising:

a directory reading module, used to obtain the target document to be extracted, and read the document directory corresponding to the target document;

a document extraction module for extracting all subdocuments nested in the target document from the document directory;

The content identification module is configured to identify the document content of each sub-document respectively, so as to identify whether confidential information exists in the sub-document.

To achieve the above purpose, the present application provides an electronic device, including:

memory for storing computer programs;

The processor is configured to implement the steps of any one of the methods for extracting nested documents disclosed above when executing the computer program.

In order to achieve the above object, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, any one of the aforementioned nested document extractions is implemented. steps of the method.

It can be seen from the above solutions that a nested document extraction method provided by the present application includes: acquiring a target document to be extracted, and reading a document directory corresponding to the target document; extracting the target document from the document directory All nested sub-documents; the document content of each sub-document is identified separately to identify whether confidential information exists in the sub-documents. As can be seen from the above, the present application can extract all sub-documents nested therein based on the document directory of the target document to be extracted, realize the extraction of the nested documents, and then identify the content of the sub-documents to determine whether there is confidential information in the sub-documents. , which can effectively avoid information leakage.

The present application also discloses an apparatus for extracting nested documents, an electronic device, and a computer-readable storage medium, which can also achieve the above technical effects.

It is to be understood that the foregoing general description and the following detailed description are exemplary only and do not limit the application.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a compositional architecture diagram of a nested document extraction system under a specific implementation disclosed in an embodiment of the application;

2 is a flowchart of a method for extracting nested documents disclosed in an embodiment of the present application;

3 is a flowchart of another method for extracting nested documents disclosed in an embodiment of the present application;

FIG. 4 , FIG. 5 , and FIG. 6 are respectively schematic diagrams of directories for different versions of documents in another nested document extraction method disclosed in the embodiment of the present application;

7 is a flowchart of yet another nested document extraction method disclosed in an embodiment of the present application;

FIG. 8 , FIG. 9 , and FIG. 10 are schematic diagrams of directories for different versions of documents in yet another nested document extraction method disclosed in an embodiment of the present application;

11 is a structural diagram of an apparatus for extracting nested documents disclosed in an embodiment of the present application;

12 is a structural diagram of an electronic device disclosed in an embodiment of the application;

FIG. 13 is a structural diagram of another electronic device disclosed in an embodiment of this application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the prior art, there is a general need to extract document content in current leaked DLP products, and most DLP products only support the extraction of current document content, but not nested documents, or even multi-layer nested document content. Therefore, if the user embeds the confidential information file into the document, the leaking system cannot analyze the confidential information file, which may lead to the leakage of the confidential information.

Therefore, the embodiment of the present application discloses a method for extracting nested documents, which can realize the extraction of nested documents, thereby effectively avoiding information leakage.

For ease of understanding, a system architecture to which the technical solutions of the present application are applied will be introduced below. Referring to FIG. 1, it respectively shows the composition architecture of a nested document extraction system of the present application. As shown in FIG. 1 , the nested document extraction system of the present application may specifically include a user terminal 11 and a server 12 , and a communication connection between the user terminal 11 and the server 12 is performed through a network 13 . The above-mentioned user terminal 11 and the server 12 may further include elements such as a processor, a memory, a communication interface, an input unit, a display, and a communication bus, and the processor, the memory, the communication interface, the input unit, and the display are all completed through the communication bus. communication with each other.

In a specific implementation, the user can transmit files through the user terminal 11 , for example, upload the file to the server 12 , or transmit the file to other communication terminals through the server 12 . Specifically, the user terminal 11 may specifically include, but is not limited to, data processing devices such as smart phones, tablet computers, wearable devices, and desktop computers.

It can be understood that the server 12 is specifically configured to identify the content of the document after acquiring the file transmitted by the user, and if the file is a nested document, extract the nested document to identify whether the transmitted file exists. Confidential information, and send risk alerts when confidential information exists to avoid information leakage. The above-mentioned servers 12 may include, but are not limited to, cloud servers, physical servers, virtual servers, and the like.

It should be pointed out that the network 13 in this application can be determined according to the network conditions and application requirements in the actual application process, and it can be either a wireless communication network, such as a mobile communication network or a WiFi network, or a wired communication network; It can be a wide area network, or a local area network when circumstances permit.

Referring to FIG. 2 , a nested document extraction method disclosed in an embodiment of the present application includes:

S101: Obtain a target document to be extracted, and read a document directory corresponding to the target document;

In this embodiment of the present application, the target document to be extracted can be acquired through the import interface, and the document directory corresponding to the target document can be read.

As a feasible implementation manner, after acquiring the target document to be extracted, the embodiment of the present application may further determine the document type corresponding to the target document, so as to read the document directory corresponding to the target document according to the document type.

S102: Extract all subdocuments nested in the target document from the document directory;

In this step, the subdocuments nested in the target document may be determined based on the document directory, and all subdocuments are extracted from the document directory.

S103: Identify the document content of each sub-document respectively to identify whether confidential information exists in the sub-document.

In a specific implementation, after all the sub-documents are extracted, the document content of each sub-document can be identified respectively, so as to determine whether there is confidential information in the sub-documents. If there is confidential information, the corresponding risk prompt information can be returned to avoid information leakage.

It should be noted that the above confidential information may specifically include, but is not limited to, financial data, customer profile information, technical data, source code, office letter data, business plans and other sensitive information. When judging whether there is confidential information in a document, basic detection methods such as regular expressions and keywords can be used for content search and matching, and basic detection methods can be used to detect clear sensitive information content. In addition, accurate data comparison detection methods, fingerprint document comparison detection methods, and vector classification comparison detection methods can also be used to further improve the detection accuracy. Among them, the accurate data comparison detection method is used to compare and detect structured data, such as the user's name, ID number, bank account number, etc.; the fingerprint document comparison detection method is used to detect unstructured data, such as office letter data, business scheme, etc.; the vector classification comparison detection method is suitable for detecting data with unique characteristics, such as financial data, source code, etc.

It can be understood that, before identifying the document content of each subdocument, it can be first determined whether the subdocument is a single document or a nested document. If the subdocument is a single document, the content of the subdocument can be directly extracted and recognized according to the document format corresponding to the subdocument; if the subdocument is a nested document, the subdocument is regarded as a new target document, and the current target document Perform extraction, that is, enter the step of extracting all subdocuments nested in the target document from the document directory again to perform iterative extraction.

It can be seen from the above solutions that a nested document extraction method provided by the present application includes: acquiring a target document to be extracted, and reading a document directory corresponding to the target document; extracting the target document from the document directory All nested sub-documents; the document content of each sub-document is identified separately to identify whether confidential information exists in the sub-documents. As can be seen from the above, the present application can extract all sub-documents nested therein based on the document directory of the target document to be extracted, realize the extraction of the nested documents, and then identify the content of the sub-documents to determine whether there is confidential information in the sub-documents. , which can effectively avoid information leakage.

The embodiment of the present application discloses another method for extracting nested documents. Compared with the previous embodiment, this embodiment further describes and optimizes the technical solution. See Figure 3, specifically:

S201: Obtain a target document to be extracted, and determine a document type corresponding to the target document;

S202: If the document type is the document type of the first type of version format, read the composite document directory corresponding to the target document; the first type of version format includes any one of doc format, xls format, and ppt format ;

In this embodiment of the present application, after acquiring the target document to be extracted, the document type corresponding to the target document is first determined. If the document type is the document type of the first type of version format, that is, the document of the office2003 version, the compound document directory corresponding to the target document is read. The first type of version format may include, but is not limited to, doc format, xls format, and ppt format.

It should be noted that the documents of the Office2003 version are stored in the compound document format. A compound document is a document that contains not only text, but also graphics, spreadsheet data, sound, video graphics, and other information. A compound document divides data into many streams, which are stored in different repositories, and all streams are divided into smaller blocks of data, called sectors, and the entire file consists of a file header structure and all the sectors that follow, The size of the sector is specified in the header structure, and all sectors are of the same size. A directory is an internal control flow consisting of a series of directory entries, each of which points to a repository or stream of compound documents, enumerated in the order in which they appear in the directory stream. The nested document in office2003 also exists in the form of a directory entry.

S203: Extract all subdocuments nested in the target document by reading all the folders of the preset files in the composite document directory;

In this step, all folders of preset files in the compound document directory may be read to extract all sub-documents stored in each folder.

Specifically, as shown in Figure 4, the word nested file in doc format is in each folder named underline and 10 numbers under the decompressed ObjectPool file, and each folder stores a nested sub-document , such as subdocuments embedded in docx, xlsx, pptx formats, each subdocument is stored in a package file stored in ole format. In addition, it is necessary to reprocess the extracted data redundant content other than the folder. As shown in Figure 5, the excel nested file in xls format is in a folder named after the decompressed MBD plus 8 hexadecimal numbers, and each file stores a nested sub-document. As shown in Figure 6, the nested file in ppt format is stored in the PowerPoint Document file, and the nested file can be extracted by finding the rectype value, and the nested file is in the rectype of RT_ExternalOleObjectStg.

S204: Identify the document content of each sub-document respectively to identify whether confidential information exists in the sub-document.

It can be understood that, when identifying each sub-document, if the sub-document is a single document, it can be extracted according to a specific document format. For example, if the name of the directory entry object is WordDocument, the doc document format is extracted; if the directory entry object name is workbook, the xls document format is extracted; if the directory entry object name is PowerPointDocument, the ppt document format is extracted. When a document is extracted, the start and length specified in the directory entry structure respectively indicate the specific content of the document.

The embodiment of the present application discloses another method for extracting nested documents. Compared with the previous embodiment, this embodiment further describes and optimizes the technical solution. See Figure 7, specifically:

S301: Obtain a target document to be extracted, and determine a document type corresponding to the target document;

S302: If the document type is a document type of the second type of version format, decompress the target document, and read the multi-level document directory corresponding to the target document after decompression; the second type of version format Including any one of docx format, xlsx format, pptx format;

In this embodiment of the present application, after acquiring the target document to be extracted, the document type corresponding to the target document is first determined. If the document type is the document type of the second type of version format, that is, the document of the office2007 version, the target document is decompressed, and after decompression, the multi-level document directory corresponding to the target document is read. The second type of version format may include, but is not limited to, docx format, xlsx format, and pptx format.

S303: Read the preset subdirectory under the multi-level document directory corresponding to the target document;

S304: Extract all sub-documents stored in the preset sub-directory;

It should be noted that, after obtaining the multi-level document directory corresponding to the target document, the preset subdirectory can be read, and all subdocuments stored in the preset subdirectory can be extracted.

In the specific implementation, as shown in Figure 8, the docx document format is stored in a compressed package. After the document is decompressed, it can be seen that the nested documents are stored in the embeddings directory under the word directory. For example, there are two embedded documents in the docx document on the left. set of documents, there are two nested documents oleObject1.bin and oleObject2.bin documents in the corresponding embeddings. The xlsx nested document format is stored in a compressed package. After the document is decompressed, you can see that the nested document is stored in the embeddings directory under the xl directory. As shown in Figure 9, there are two nested documents in the document on the left, corresponding to The embeddings exist two nested documents oleObject1.bin and oleObject2.bin files. As shown in Figure 10, the extraction of pptx nested documents can refer to the above content.

S305: Identify the document content of each sub-document respectively to identify whether confidential information exists in the sub-document.

It is understandable that since the office2007 series documents are stored in the ZIP compressed format, the ZIP archive can be decompressed cyclically to read nested objects. Specifically, if the word/document.xml file exists after decompression, the content of the docx document is extracted; if the xl/sharedString.xml file exists after decompression, the content of the xlsx document is extracted; if there is ppt/slides/slideX after decompression .xml file, extract the content of the pptx document; if it is another file after decompression, take the file as the target document to be extracted, and return to step S301 to perform the file type identification process.

An apparatus for extracting a nested document provided by an embodiment of the present application is introduced below. The apparatus for extracting a nested document described below and a method for extracting a nested document described above may refer to each other.

Referring to FIG. 11 , a nested document extraction apparatus provided by an embodiment of the present application includes:

A directory reading module 401, configured to acquire a target document to be extracted, and read a document directory corresponding to the target document;

a document extraction module 402, configured to extract all subdocuments nested in the target document from the document directory;

The content identification module 403 is configured to identify the document content of each sub-document respectively, so as to identify whether confidential information exists in the sub-document.

For the specific implementation process of the foregoing modules 401 to 403 , reference may be made to the corresponding content disclosed in the foregoing embodiments, which will not be repeated here.

The present application also provides an electronic device. Referring to FIG. 12 , the electronic device provided by the embodiment of the present application includes:

a memory 100 for storing computer programs;

The processor 200 can implement the steps provided in the above embodiments when executing the computer program.

Specifically, the memory 100 includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer-readable instructions, and the internal memory provides an environment for the operation of the operating system and the computer-readable instructions in the non-volatile storage medium. The processor 200 may be a central processing unit (CPU), controller, microcontroller, microprocessor or other data processing chip in some embodiments, providing computing and control capabilities for electronic devices, executing the memory When the computer program stored in 100 is used, the steps of the method for extracting nested documents disclosed in any of the foregoing embodiments can be implemented.

On the basis of the above-mentioned embodiment, as a preferred implementation manner, as shown in FIG. 13 , the electronic device further includes:

The input interface 300 is connected to the processor 200 , and is used for acquiring externally imported computer programs, parameters and instructions, which are stored in the memory 100 under the control of the processor 200 . The input interface 300 can be connected with an input device to receive parameters or instructions manually input by the user. The input device may be a touch layer covered on the display screen, or a key, a trackball or a touchpad provided on the terminal shell, or a keyboard, a touchpad, or a mouse, or the like.

The display unit 400, connected to the processor 200, is used for displaying data processed by the processor 200 and for displaying a visual user interface. The display unit 400 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode, organic light-emitting diode) touch device, and the like.

The network port 500 is connected to the processor 200 and is used for communicating with external terminal devices. The communication technology used for the communication connection can be wired communication technology or wireless communication technology, such as Mobile High Definition Link Technology (MHL), Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), Wireless Fidelity Technology (WiFi), Bluetooth communication technology, Bluetooth low energy communication technology, communication technology based on IEEE802.11s, etc.

FIG. 13 only shows the electronic device having the components 100-500. Those skilled in the art can understand that the structure shown in FIG. 13 does not constitute a limitation on the electronic device, and may include fewer or more components than those shown in the figure. components, or a combination of certain components, or a different arrangement of components.

The present application also provides a computer-readable storage medium, which may include: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk Or various media such as optical discs that can store program codes. The storage medium stores a computer program, and when the computer program is executed by the processor, implements the steps of the method for extracting nested documents disclosed in any of the foregoing embodiments.

The present application can extract all nested sub-documents based on the document directory of the target document to be extracted, realize the extraction of nested documents, and then identify the content of the sub-documents to determine whether there is confidential information in the sub-documents, which can effectively avoid Information disclosure.

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present application, several improvements and modifications can also be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities or operations. There is no such actual relationship or sequence between operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Claims (10)

1. A nested document extraction method, comprising:

acquiring a target document to be extracted, and reading a document directory corresponding to the target document;

extracting all sub-documents nested in the target document from the document directory;

and respectively identifying the document content of each subdocument to identify whether confidential information exists in the subdocument.

2. The method for extracting the nested document according to claim 1, wherein after the target document to be extracted is obtained, the method further comprises:

determining a document type corresponding to the target document;

the reading of the document directory corresponding to the target document includes:

and reading a document directory corresponding to the target document according to the document type.

3. The method for extracting the nested document according to claim 2, wherein the reading the document directory corresponding to the target document according to the document type includes:

if the document type is in a first version format, reading a composite document directory corresponding to the target document; the first version format comprises any one of doc format, xls format and ppt format;

if the document type is the document type in the second type version format, decompressing the target document, and reading a multi-level document directory corresponding to the target document after decompression; the second type of version format includes any one of a docx format, an xlsx format, and a pptx format.

4. A nested document extraction method according to claim 3, wherein extracting all sub-documents nested in the target document from the document directory comprises:

and extracting all the sub-documents nested in the target document by reading all the folders of the preset file in the compound document directory.

5. A nested document extraction method according to claim 3, wherein extracting all sub-documents nested in the target document from the document directory comprises:

reading preset subdirectories under a multilevel document directory corresponding to the target document;

and extracting all the subdocuments stored in the preset subdirectory.

6. A nested document extraction method according to any one of claims 1 to 5, wherein before identifying the document content of each subdocument separately, the method further comprises:

judging whether the subdocuments are single documents or nested documents;

and if the subdocuments are nested documents, taking the subdocuments as the target documents, and performing iterative extraction by the step of extracting all the subdocuments nested in the target documents from the document directory.

7. A nested document extraction method according to claim 6, wherein the identifying the document content of each subdocument separately comprises:

and if the subdocuments are single documents, directly extracting and identifying the contents of the subdocuments according to the document formats corresponding to the subdocuments.

8. A nested document extraction apparatus, comprising:

the catalog reading module is used for acquiring a target document to be extracted and reading a document catalog corresponding to the target document;

the document extraction module is used for extracting all the sub-documents nested in the target document from the document directory;

and the content identification module is used for respectively identifying the document content of each subdocument so as to identify whether confidential information exists in the subdocument.

9. An electronic device, comprising:

a memory for storing a computer program;

a processor for implementing the steps of the nested document extraction method of any one of claims 1 to 7 when executing said computer program.

10. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, carries out the steps of the nested document extraction method of any one of claims 1 to 7.

Images