About Virus Pattern File Numbering

If multiple files exist in the same directory, only the one with the highest number is used because the most recent pattern file will have the highest number. There is no need to delete the old pattern file or take any special steps to "install" the new one. You can find the current virus pattern file, scan engine, and other files on the Summary page.

Pattern files use the following naming format:

lpt$vpn.###

where ### represents  the pattern version (for example, 511).

To accommodate pattern versions greater than 999, Trend Micro introduced an extended internal versioning system:

roll number.pattern version.build number (format: xxxxx.###.xx)

• roll number—represents the number of rounds when the pattern version exceeded 999 and could be up to five digits (ranging from 0-42948).

• pattern version—the same as the pattern extension of lpt$vpn.### and contains three digits (ranging from 100-999).

• build number—represents the patch or special release number and contains two digits (ranging from 00-99).

The minimum version number is 0.100.00 and the maximum version number is 42948.672.96.