Google is suing an alleged Chinese-speaking cybercriminal group it says helped drive a sprawling phishing operation that targeted Americans with fraudulent text messages impersonating government agencies and major companies, NBC News reported.

In the legal complaint filed Tuesday, Google alleges the group, known as Darcula, sells software that makes it easy to launch large-scale “smishing” campaigns, allowing scammers with little technical skill to send phishing texts en masse while posing as organizations such as the IRS and the U.S. Postal Service, according to NBC News.

Google said the lawsuit is aimed less at identifying and arresting the group and more at dismantling the web infrastructure that enables the scams. A company spokesperson told NBC News that the legal action is intended to establish standing in U.S. courts so Google can seek to seize websites used in the operation.

In its court filing, the tech giant claims that Darcula and associates have stolen nearly 900,000 credit card numbers to date, including nearly 40,000 from Americans. From September to November, Google received more than 5,000 complaints from people using Google Messages about Darcula scam texts, according to NBC News.

At the center of the allegations is Darcula’s signature program, called Magic Cat, which NBC News described as an intuitive tool that lets scammers blast messages to millions of phone numbers and direct victims to convincing fake websites. Those sites can mimic services such as YouTube’s paid offering and are designed to capture credit card numbers entered by victims. 

An investigative report by Norwegian National Broadcasting (NRK) published earlier this year found more than 600 scam operators behind the Magic-Cat scams. 

Google’s lawsuit names a suspected leader, Yucheng Chang, and 24 additional defendants who are unnamed and whose identities Google says it does not know, according to the report. Google alleges Chang lives in China and that other members are based in China or other countries, according to NBC News.

In videos previously posted to a Darcula Telegram channel, the group promoted how the software could be customized to send waves of texts to Americans claiming they owed unpaid E-ZPass tolls, according to the report. 

In a statement to the news outlet, Cassandra Knight, Google’s vice president of litigation, said the company was “taking legal action to shut down the infrastructure of a massive scam operation that was responsible for 80% of all phishing texts.” 

“Our message to scammers is clear: We will use our technical and legal resources to protect our users and hold you accountable,” Knight said in the report.

Read more at NBC News