WordFence scan problems

Error message
This file may contain malicious executable code: .../wp-content/plugins/smart-slider-3/nextend/library/libraries/zip/pclzip.php
Filename: wp-content/plugins/smart-slider-3/nextend/library/libraries/zip/pclzip.php
File type: Not a core, theme or plugin file.
Issue first detected: 5 mins ago.
Severity: Critical
Status New

This file is a PHP executable file and contains the word ‘eval’ (without quotes) and the word ‘unpack(‘ (without quotes). The eval() function along with an encoding function like the one mentioned are commonly used by hackers to hide their code. If you know about this file you can choose to ignore it to exclude it from future scans.

Cause
We use that file for zipping at the exporting/importing of our sliders. The 'eval' functions are commented out in it, just it looks like WordFence doesn’t check that. And the 'unpack' function is necessary for the unzipping, so you can ignore this, as their message says too, that "If you know about this file you can choose to ignore it to exclude it from future scans." and the file is perfectly safe.