Here is a little walkthrough:
First of all you will need to play a few games in the Combat Arena for some Tokens to buy some upgrades from the Armax store:
Bronze Token (1) for the Spin Zone map.
Silver Tokens (7 or 8) for Difficulty/Score modifiers, Elite enemies and Reapers.
Gold Token (2) for Super Elite enemies and Collectors.
(Remember you can cash in 1 Gold for 3 Silver and 1 Silver for 3 Bronze).
(Thanks to eViL mOnKeY 270 for pointing out that you need to unlock enemy factions as well).
Once done, head down to the Combat Sim Controls and check your messages, there should be one named "Unusual Scores" in which you are asked to help the Armax IT people find a bug in the program.
This will contain of 3 matches:
1. Finish a game against Super Elite enemies.
- Map: Wingman
- Enemy: Reapers recommended, but any enemy will do
- Challenge: Super Elite
- Score modifier: Whatever you like
From the starting point, turn left and into the far corner on the lowest floor.
Get youself behind the very last cover point and place your squad mates at the two cover points before you.
You should be able to pick off enemies from quite a distance.
Banshees only show up in the last wave.
Also, do not run for the bonuses as the game could make this safe place a spawn zone.
2. You get the message "Early Testing Results".
You will need to finish a game with maxmimum score bonus.
Turn on:
- No Medi-Gel
- One-Shot Player Shields
- Enhanced Enemy Shiels
- Enemy Damage Boost
- No Placed Ammo
This will net you 60% score bonus.
- Do NOT select Player Damage Boost!
- Map: Wingman
- Enemy: Whatever you want
- Challenge: Foot Soldiers
Same tactic as before
3. You get the message "Memory Leak Isolated".
You will have to finish a game against Elite Geth on Spin Zone with "Enhanced Enemy Shields" on.
- Map: Spin Zone
- Enemy: Geth
- Challenge: Elite
- Score Modifier: Enhanced Enemy Shields
You can also select Enhanced Damage Boost if you want.
Set it up this way and you will notice that the map will go all crazy.
You will face a total of 5 Waves against Super Elites only.
Waves 1-4 will be Super Elites from one enemy faction per wave.
Wave 5 will have only boss-level enemies from all factions combined.
A good point to stay would be the area just in front of you after starting, the L-shaped cover.
After completing all 5 waves, you will get the achievement.
Oh and if you really have difficulties accomplishing any of those, just set the "Combat Difficulty" setting in the options menu to "Narrative".
Piece of cake doesn't even describe it.