Washington/IBNS: The US Justice Department announced that it had successfully taken down a complex malware network that had been utilized by Russia's FSB intelligence agency for the past 20 years to conduct espionage in 50 countries, including a member of NATO, on Tuesday.

The FSB had managed to infiltrate computer systems worldwide with the "Snake" or "Uroburos" malware, with a specific focus on government networks, research facilities, journalists, and other designated targets, as per AFP's report,

US officials have revealed that the compromised computers were also used as relay nodes to conceal traffic to and from the Snake malware that had been implanted on targeted computer systems.

The Justice Department described the malware network as "sophisticated" the malware network.

According to them, the FBI carried out a multi-year operation to defeat the Snake malware. This involved inserting a piece of their own computer code into the malware, which gave commands that caused it to overwrite itself, leading to its defeat.

Computer security experts have been aware of the Snake malware for over a decade, and the US cyber defense agency, CISA, has revealed that the FSB began developing it back in 2003.

CISA has labeled Snake as "the most sophisticated cyber espionage tool in the FSB's arsenal," citing its remarkable stealth, making it difficult to detect in computer systems and network traffic.

Additionally, the malware was designed for effortless updating and modification, yet contained "surprisingly few bugs given its complexity."

These attributes enabled the FSB to operate unnoticed for many years, infiltrating computers with sensitive documents through sprawling host networks.

CISA has also disclosed that the FSB was able to place Snake on the systems of at least one unnamed NATO country, giving Russian intelligence access to and extraction of sensitive international relations documents and diplomatic communications.

"The effectiveness of this type of cyber espionage implant depends entirely on its long-term stealth," said the agency.