WASHINGTON, April 24 (Reuters) - Technology firm Cisco

Systems ( CSCO ) said that hackers have subverted some of its

digital security devices to break in to government networks

globally.

In a blog post published on Wednesday, the company said its

Adaptive Security Appliances - pieces of equipment that roll

several different digital defense functions into one - had

previously unknown vulnerabilities that had been exploited by a

group of hackers they called "UAT4356."

The blog post described the group as a "sophisticated

state-sponsored actor" and said that the company's investigation

found victims that "involved government networks globally."

Cisco ( CSCO ) said the vulnerabilities have been patched.

In a statement, the company said it urged customers to take

"immediate action" to update their software. It did not give

further details on the breaches, which it said dated back to

earlier this year.

Security equipment like routers and other so-called edge

devices has become an increasingly popular vector for advanced

hackers because it resides at the perimeter of a target's

network and can be difficult to monitor.

In its post, Cisco ( CSCO ) warned that it had seen evidence that the

UAT4356 hackers were interested in "and potentially attacking"

network devices from Microsoft ( MSFT ) and other vendors.

Microsoft ( MSFT ) did not immediately return an email.

The Cybersecurity and Infrastructure Security Agency (CISA)

said it had "not confirmed evidence of this activity affecting

U.S. government networks at this time." CISA released an alert

on the Cisco ( CSCO ) vulnerabilities on Wednesday.