opening .mdf file to steal data

Heisenberg 261 Reputation points
2023-02-03T20:12:50.58+00:00

hi folks,

  1. what are the ways someone can open .mdf file. When the instance is running and database is online noone can open .mdf file. So what are the ways someone can open .mdf file.
  2. even if someone is able to open .mdf file what data can they read. i see some character data is not encrypted. So what data is readable and what is not.
  3. Database for which .mdf and .ldf files are not encrypted by some mechanism like TDE , what are the ways someone can copy these files EVEN IF instance is runing and database is online.

thank you

SQL Server
SQL Server
A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
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  1. Erland Sommarskog 100.8K Reputation points MVP
    2023-02-03T22:23:57.9833333+00:00

    On the machine itself, it is difficult to access the database files if SQL Server is running. But if you have made your inroads to the machine so that you have permission to access the files, you are likely to have permissions to kill SQL Server as well.

    If there is a backup tool that uses the VSS service, VSS can instruct SQL Server to freeze the database, so that the backup tool can take a consistent backup of the files. (Such backup tools work on volume level.)

    If the database is on a SAN, the SAN administrator can take a shadow copy of the entire volume. Note that the SAN administrator does not need access to the machine where SQL Server is running.

    Once you have the MDF files, there are no problems to read it. The easiest way is of course to attach it to an SQL Server instance, but the file format is not exactly a secret,

    And, yes, by default, the data is stored unencrypted. You can apply TDE, Transparent Data Encryption to encrypt the files. With TDE, only stealing the MDF will take you no where. Then again, if you have access to the machine, getting the keys are not that difficult. (But for the SAN admin, there is now an uphill battle.)

  2. Seeya Xi-MSFT 16,436 Reputation points
    2023-02-06T08:13:00.05+00:00

    Hi @heisenberg ,

    Welcome to Microsoft Q&A!

    Please refer to this similar thread: https://stackoverflow.com/questions/5497471/protecting-sql-server-database-file

    Hope this would give you some help.

    Best regards,

    Seeya

    If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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  3. ansar ullah 0 Reputation points
    2023-12-02T17:49:52.1266667+00:00

    Opening a .mdf file can be done using SQL Server Management Studio (SSMS) or command-line tools to attach the database. Unauthorized access might allow reading unencrypted data. Copying .mdf files is possible through methods like creating a backup, detaching the database, or using Volume Shadow Copy. Implementing encryption mechanisms like Transparent Data Encryption (TDE) helps secure data at rest, and securing file permissions, monitoring, and regular backups are crucial for overall database security. Always follow best practices and obtain proper authorization to avoid legal and ethical .issues

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