Kicking back on Sunday night, I got a text from my business partner, Michelle: Our website had been hacked — by ISIS, the Islamic State.

OK, we don’t really know who did it — but the ISIS flag had replaced the usual shot of our salon, along with the words “Hacked by Islamic State (ISIS)” and “We are everywhere ;)”; that’s enough for me.

Why us? We own Fix Beauty Bar, a blowout-and-nail bar on the Upper East Side. Not an obvious target for Islamists.

Maybe they hate women who pursue their own goals?

I’m a writer, she’s a real-estate agent; our joint dream was to open up a unique business, somewhere women could get their hair and nails done at the same time, and we went for it.

Two and a half years later, we’re a staple for busy New York City women.

Was it something I’d written recently? ISIS isn’t exactly my beat. Are the Islamic Staters big Taylor Swift fans? Supporters of alternate side parking regulations? Into Gifted&Talented testing for 5-year-olds?

No. No, it wasn’t anything I had written. It wasn’t any one thing Michelle or I had done or said or thought.

It was everything we’d done or said or thought. Ever.

They hated us, they hacked us, they tried to hurt our business because we live in the free world. No other reason.

Not that the attack hurt much — it just replaced our regular image with their banner; it didn’t stop anyone from clicking through to make an appointment, as 80 percent of our clients do.

Still, it wasn’t exactly “random,” as the president had described the post-Charlie Hebdo attack in a Kosher market in Paris (which wasn’t truly random at all, of course).

It’s not as if ISIS is hacking websites in Saudi Arabia, where its ideology might have a sympathetic ear, or in Syria and Iraq, where its lunacy has a foothold.

ISIS could hack pretty much any business in America and be fairly confident that it’s not hurting one of its supporters.

Indeed, pro-ISIS hackers have hit a string of US sites lately. The Eldora Speedway site was hacked with the same “We are everywhere ;)” message as ours. So was the site for Long Island’s historic Montauk Manor.

I don’t need to know who owns these businesses to know they don’t support the savages who cut off heads, burn men alive in cages or feed the ground-up corpse of a son to his mother. Just a guess.

Social-media addict that I am, I eventually tweeted out news of the hack — and got a few comments suggesting I’d made it up, or that it wasn’t really ISIS. I’m a naturally skeptical person, too, so I wasn’t offended.

Still: Our first instinct, on seeing the hack, was to keep it quiet and have our site-hosting service fix it before anyone noticed. We keep no confidential data on the site, but being associated with ISIS can’t exactly be good for business, what with the aforementioned person-burning and beheadings.

In other words, our initial reaction was fearful. For all our talk about “not letting the terrorists win,” the hacker — whether “official” ISIS or just some loser causing chaos in its name — got to us, in some small way.

That’s why I’m writing now: As the point of terrorism is to terrorize, we decided pretty quickly that we weren’t going to let them make us afraid. Our site is back and we’re open for business.

Fight terror: Come in for a blowout and manicure!