There are VS* temp files in the OfficeScan agent's C:\Program Files (x86)\Trend Micro\OfficeScan Client\Temp directory.
The VS* temp files under the C:\Program Files (x86)\Trend Micro\OfficeScan Client\Temp directory are generated by Scan Engine (VSAPI) while scanning files and they are not harmful.
Furthermore, the number of temp files created for a single target file depends on the file type and content. It is possible to see a great number of temp files generated when an archived file containing many files is being scanned.
In normal conditions, Scan Engine will delete the temp files every time after its use. However, when Scan Engine is forcibly terminated/de-initialized by the system or the caller (product), it might not have the chance to finish the scanning and clean-up operation. The execution of the code running into a defect and causing an exception during the scanning can also result in the garbage temp files left there.
If further assistance is needed, contact Trend Micro Technical Support.