In his latest broadside against big business, Sen. Bernie Sanders, I-Vt., is introducing a bill Thursday that would prevent large companies from buying back stock unless their employees are paid at least $15 an hour.

The proposal is aimed squarely at the nation's largest bricks-and-mortar retailer: Walmart, which announced earnings Thursday that beat analysts' expectations though revenue missed forecasts. The legislation is titled The Stop WALMART Act, or The Stop Welfare for Any Large Monopoly Amassing Revenue from Taxpayers Act.

"The Walton family, the owners of Walmart, are the wealthiest family in America with a net worth of about $180 billion. Meanwhile, most Walmart retail workers are working for horrendously low wages with minimal benefits," Sanders said in a statement to CNBC. "The wealthiest family in America must pay its workers a living wage."

After passage of GOP tax cuts, Walmart did increase its starting wage rate for hourly employees in the U.S. to $11 and expand some benefits. Still, the boost falls short of Sanders' target.

The new bill is co-sponsored by Rep. Ro Khanna, D-Calif. It would also require large employers to give workers up to seven days of paid sick leave for themselves or to care for a family member. In addition, it caps executive compensation at 150 times the median employee wage. Under the bill, companies with more than 500 workers would face these new restrictions.

Sanders, who identifies as a democratic socialist and caucuses with Democrats in the Senate, is one of the most vocal critics of what he deems unfair business practices and is an aggressive advocate for raising the minimum wage. He proposed a similar bill in September – called the BEZOS Act – aimed at Amazon and has vowed to reintroduce legislation raising the federal minimum wage from $7.20 to $15 an hour when the next session of Congress convenes in January.

Sanders later praised Amazon CEO Jeff Bezos for hiking the minimum wage at the company.