Lamium purpureum.

It is not a native plant.

wow. any advice?

I would have thought that someone on this forum would have been more forthcoming in offering help. I am a newbie gardener, so maybe if I offer advice someone will jump in and correct me.

Personally I would never use weed-killer. Weed killer is responsible for the deformities and deaths of many frogs across the country.

So I think getting to it and pulling it (especially before it goes to seed) is your best option. From what I read on other garden forums, they are easy to pull.

We been dealing with the related henbit since stopping our preemergent use a few years back. They go away in the heat of summer, but can produce thousands of seeds per plant so will be back unless you break the seed cycle. Keep them cut or pulled before they go to flower. Where they are already in bloom, catch and bag the cuttings if you have a catcher on your mower. I'd do this over resorting to a broadleaf weed killer, especially at this time of year. Improving the overall health of the lawn or ground cover in the infested areas will also help a lot.

Fall is the next opportunity to consider applying a preemergent to get it back where the manual methods (cutting/pulling) can keep it under control.

you could try strong vinegar or fire to burn it out (carefully). I've even see boiling water suggested.

It's pretty easy to just pull out and good exercise too. ;) Also the most inexpensive option if you're frugal like me.