Is wmartsale.com a Walmart site or a hacker site?

Definitely not a Walmart site. Don't click it or any other suspicious links, ever.

Notice it is not walmart.com, they didn't break into anything. If it were a walmart site it would be more like walmart.com/sale . Then they would've had to break into the site. This is a "dropnet" type infection attempt, a lot of fish (people/targets) will get away by deleting or ignoring it, but a lot of people will click it and if vulnerabilities that are being targeted fit-- the computer/phone gets infected and they do with it what they please. Whatever you do, don't click it to find out...leave that to the researchers and antivirus employees.

The take-away from this is your phone is a computer-- no matter the OS or type, it can get infected. Think about it. If you have a smart phone your life is probably on there. So bite the bullet and at least put some AV software on there from a reputable company. Just remember you get what you pay for and a free AV from a no-name company probably won't be effective and is another way the bad guys try to infect your phone/computer.