Anti-Corruption Defender

Anti-Corruption Defender is file integrity monitoring application for Windows that validates integrity of files stored on all types of media (hard drives, dvds, ...) using a verification method between initially captured state and current state using SHA-1 checksums.
Once volumes or particular folders are added to the application, they are automatically and periodically scanned in attempt to identify latent corruption and to trigger appropriate alerts that will help with data repair.


Application is portable. Download and unpack it on your hard drive into a location where application can create data - it will create database file and log file in the same directory as executable. Application requires .NET Framework 4.5 installed.

Once extracted it is possible to set autostart for application, from Tools menu, select Run application on startup

Monitoring folders

Anti-Corruption Defender is automatically monitoring folders added to it. It is possible to add any folder in the application with Add folder toolbar button.

Application will start indexing of files immediately if confirmed and fully automatically from this point (e.g. application recognizes when drive is connected to the system and starts indexing and verification of files immediately, when required or configured).

It is possible to start indexing and verification of files also manually from toolbar
  • Run itegrity check for available drives - verifies if content of files changed, reports deleted files and indexes new files
  • Index new files only for available drives - reports deleted files and indexes new files

It is also possible to select one or more configured folders and by pressing right mouse button open context menu:

Folder setup

There are configuration options available for folder. Settings dialog can be opened by left mouse double click on folder. Configuration options are:

  • Number of days after which checksums must be verified - value indicates how often should be checksums verified
  • Comma separated list of ignored extensions - application will ignore files with these extensions
  • Line separated list of ignored folder root relative paths - application will ignore files on these paths, if path is file - that one file is ignored, if path is directory - that directory and all its subdirectories and files are ignored
  • Relocate to drive option that allows to relocate folder to drive when volume label changed and program cannot locate this folder/volume anymore. This option is shown only if folder cannot be found, drive is mounted to the system and ready.

Errors and recovery

Anti-Corruption Defender automatically scans files for latent corruption. There are three states of folder

  • OK - green color
  • Warning - data non threating, action is required, yellow color
  • Error - immediate action is required, red color

By selecting one or more folders and right clicking it is possible to generate report from context menu. Report contains information about all issues that is needed for recovery.

Warning state

Warning state is caused by

  • application interrupted by user or system (PC shuts down)
  • drive being ejected from system forcefully during scan
  • error occurring during file scan - e.g. insufficient privileges
  • files needs verification of checksums (last checksums were verified too long ago - according to value set up in folder settings)


Remove issue from system - e.g. configure permissions on files - and start Index new files only operation on folder. In case warning is caused by "Old test age" or file access error for already indexed files, it is necessary to start full folder/drive scan in order to remove this issue. It is also possible to remove warning in folder context menu Clear issues, if you do not care, however this does not clear "Old test age" warning.

Error state

Error state occurs when deleted files or changed files are found during scan.


Deleted files - means that file disappeared from its original location. Restore file from backup and start Index new files only operation on folder. If file moved within the same folder it is possible to use Locate deleted files tool from context menu and clear issues from there. If you do not care about deleted files clear issues from context menu.

Changed files:

Changed file is file whose content changed. Restore file from backup and start full integrity check by selecting Run integrity check in context menu. If you do not care, you can clear issues from context menu by selecting Clear issues action.

Other considerations

Anti-Corruption Defender stores data in database file located in the same directory where executable is. It is good sometimes to cleanup database file, it is possible to do so from Tools toolbar button - Compress database. It is good to backup this database file as it contains all indexing data.

Anti-Corruption Defender can be run from one place or you can use it - for example - separately on each backup drive.