WASHINGTON, Oct 18 (Reuters) - A U.S. court has ordered

Israel's NSO Group to stop targeting Meta Platforms' ( META )

WhatsApp messaging service, a development the spyware company

warned could put it out of business.

In a 25-page ruling handed down Friday, U.S. District Court

Judge Phyllis Hamilton imposed a permanent injunction on NSO

Group's efforts to break into WhatsApp, one of the world's most

widely used communications platforms.

Hamilton also handed NSO a significant break on the damages

awarded in a recently concluded jury trial, reducing the

punitive damages it owes Meta from about $167 million to $4

million.

The injunction is likely to pose a challenge to NSO, which has

for years been accused of facilitating human rights abuses

through its flagship hacking tool, Pegasus.

Pegasus takes advantage of weaknesses in commonly deployed

pieces of software to power its surveillance, making WhatsApp

one of its bigger targets.

NSO has previously argued that an injunction preventing it

from going after WhatsApp "would put NSO's entire enterprise at

risk" and "force NSO out of business," according to the

judgment.

Meta executives celebrated the decision.

"Today's ruling bans spyware maker NSO from ever targeting

WhatsApp and our global users again," WhatsApp chief Will

Cathcart said on X. "We applaud this decision that comes after

six years of litigation to hold NSO accountable for targeting

members of civil society."

NSO, which has long insisted its products fight serious crime

and terrorism, did not immediately return a message seeking

comment on the ruling.

The company was recently purchased by Hollywood producer

Robert Simmonds, according to a report earlier this month in

tech publication TechCrunch. Simmonds did not immediately return

an email.