SABOTAGE
Sabotage is a deliberate action aimed at weakening a polity or corporation through subversion, obstruction, disruption or destruction. In a workplace setting, sabotage is the conscious withdrawal of efficiency generally directed at causing some change in workplace conditions. One who engages in sabotage is a saboteur. Saboteurs typically try to conceal their identities because of the consequences of their actions.
Any unexplained adverse condition might be sabotage. Sabotage is sometimes called tampering, meddling, tinkering, malicious pranks, malicious hacking, a practical joke or the like to avoid needing to invoke legal and organizational requirements for addressing sabotage.