By AJ Vicens

Aug 20 (Reuters) - Hackers associated with some of

Russia's most prolific cyber espionage units have over the last

year been leveraging a vulnerability in older Cisco ( CSCO ) software to

target thousands of networking devices associated with critical

infrastructure IT systems, the FBI and Cisco ( CSCO ) said on Wednesday.

Hackers working within the Russian Federal Security Service

(FSB) Center 16 are extracting "device configuration information

en masse, which can later be leveraged as needed based on

then-current strategic goals and interests of the Russian

government," Cisco Talos researchers Sara McBroom and Brandon

White wrote in a threat advisory published to the company's

blog.

In a separate advisory, the FBI said that over the last year it

had detected the hackers collecting configuration files "for

thousands of networking devices associated with U.S. entities

across critical infrastructure sectors."

In some cases the configuration files are modified to enable

long-term access for the hackers, who use that access to conduct

reconnaissance in targeted networks, with a particular interest

in industrial control systems.

The Russian embassy in Washington did not respond to a

request for comment. Moscow denies conducting cyber espionage

operations.

The hackers are exploiting a seven-year-old vulnerability in

Cisco IOS software, targeting unpatched and end-of-life network

devices, according to a separate threat advisory published on

Wednesday by Cisco Talos, Cisco's ( CSCO ) threat intelligence research

unit.

Other state-backed hackers are likely conducting similar

hacking operations targeting the devices, the Cisco Talos

researchers wrote.

Organizations within the telecommunications, higher

education and manufacturing sectors across North America, Asia,

Africa and Europe have been most targeted, "with victims

selected based on their strategic interest to the Russian

government," the researchers said.

The hacking unit linked to the activity has been operating for

at least a decade, according to the researchers, and is likely a

subgroup within the FSB's Center 16. In March 2022 the U.S.

Department of Justice charged four Russian nationals within the

group of illegally targeting the global energy sector between

2012 and 2018.

(Reporting by AJ Vicens in Detroit; Editing by Daniel Wallis )