Is WPLOCKER safe?

Found that Wplocker .com have lots of nulled and cracked plugin and theme available. Is this safe to download plugin from there and use it in my website. Share your experiance. Or share some security check that I can use before using those plugin/theme in my website. (Scanned one plugin in virustotal and found no threads!)

I've downloaded a plugin called cost-calculator-builder-pro from WPLocker. I noticed a strange aspect by comparing the local plugin libraries and remote from trusted sources.
Few of them had file sizes higher than the original (indication of injection of code). I didn't verify deeper because it had lots of files, so I can't say for sure. I wouldn't expect less, they're doing that for years... Likewise, I wonder if anyone has discovered theirs strategy.