CHKLIST.MS is a "checksum" file. A checksum is an error-detection
scheme that involves creating a sum of the bits in a set of bytes of
data and using that sum to later check for a change in the data.
Checksums are commonly used in communications software to check for
data transmission errors.
In the case of Microsoft Anti-Virus, the CHKLIST file contains
checksums for certain files in the directory containing the CHKLIST
file. The checksums are based on the data contained in each file. The
checksum is stored along with each file's size, attributes, date, and
time. This information is used by Microsoft Anti-Virus during the
Detect phase to check for changes to the files in the directory.
The files are created (and updated) by Microsoft Anti-Virus during the
Detect or Detect And Clean scanning process if the Create New
Checksums option is selected in the Options dialog box.
Checksums are created for files with the following extensions:
Deleting the CHKLIST.MS Files
The CHKLIST files can be deleted. To do this, press F7 in Microsoft
Anti-Virus for MS-DOS or choose Delete CHKLIST Files from the Scan
menu in Microsoft Anti-Virus for Windows.
If you disable the use of the CHKLIST.MS files, Microsoft Anti-Virus
does not check for unexpected changes in files. (It can scan files for
known virus signatures only.)