A new ransomware, dubbed “Ryuk,” has surfaced in the last few weeks that is said to be targeting large organizations in the United States.

The attackers behind Ryuk have reportedly made over $640,000 in just two weeks, and are allegedly connected to the well-known hacking group out of North Korea—Lazarus.

According to security company Check

A new report released by Check Point has security personnel working in the health care industry particularly concerned and they are warning their colleagues about the existence of “Fireball.”

Fireball, released by a Chinese operation, has infected approximately 250 million computers worldwide. According to the report, the malware hijacks web browsers and turns computers into