A virtual currency mixer that the U.S. sanctioned last year for facilitating North Korean laundering appears to have relaunched under a new name, raising questions about the effectiveness of sanctions against such tools.

Under its new name Sinbad, the mixer formerly known as Blender has laundered nearly $100 million in bitcoin from cyberattacks attributed to North Korea’s Lazarus Group so far, blockchain analytics firm Elliptic said in an analysis released Tuesday.

The U.S. Office of Foreign Assets Control (OFAC) imposed sanctions on Blender in May after Lazarus used the mixer to launder over