To easily obtain this, go into a Private Online Party and start Virus Attack. This is a DedSec event which can be done easily solo by hiding behind an object (depending on where your objective is). The best place to hide is behind a railing above enemies or in scissor lifts. Most enemies can easily be killed if you are spotted by using the environment ot your guns.
Once done, repeat this event 5 times and the trophy will pop. If having trouble doing this solo, invite a friend or do a public session and this may make the trophy easier.