In photography, exposure is controlled by three things:
ISO: How sensitive the sensor is to light falling upon it.
Aperture: How wide of an opening is selected to allow light in -- this is fixed on the EVO.
Shutter Speed: How long the shutter stays open to allow light in -- this is determined by the camera on the EVO.
So, you point the camera at something and, based on the amount of available the camera's internal meter detects, it will adjust the ISO setting (since it's on auto by default) and, from there, determine the shutter speed it's going to use. If it's very low light, it'll throw up the LED "flash" (more of a hot light, which have even made their way into the "real" photography world) and meter the scene based on that.
So, as folks have mentioned, you have the option of hard-setting the ISO at a low value -- the lower the number, the less digital noise you'll have in your photo; however, this requires longer shutter speeds so you're more likely to get a blurry photo.
Some software handles ISO noise processing better than others, but ultimately it comes down to having a noisy photograph that's otherwise sharp or a photo that's not noisy that's not going to be tack sharp.
Your best bet is to put as much light onto your subject as possible so the camera doesn't have to resort to higher ISO's.