If it were coming out around the bleed screw, then checking the tightness of the screw and/or the condition of the o-ring it's hiding would be in order. Taking the screw out to look at the o-ring is something you should only do if you're prepared to bleed the brake, but it sounds like that's probably in order anyway. Bleed port o-rings getting out of place or mushed is a thing that happens.

You can also check the hose connection. Pull back the rubber shield around the hose and make sure the compression fitting is snugged in nice and securely. That coming loose would be kind of scary/weird so if it did happen you would definitely want to make sure all the threads, the olive, and the hose end and barb all looked good.
If it's anything else you probably need a new lever or complete brake. Aurigas are decent brakes but replacement seals and other rebuild type parts for them are unobtanium.