Hard worker — malicious software (6)
I believe the answer is:
trojan
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">hard worker</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">malicious software</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that Trojan is a type of malicious software)</span><br/ ><br/ ></span>
(Other definitions for trojan that I've seen before include "Paris for one" , "Subject of King Priam" , "Dedicated worker" , "Computer threat" , "Of Troy or its people" .)