Russian antivirus firm Kaspersky Labs claims to have found a cyber attack that may have been stealing confidential government documents since 2007 from mostly Eastern Europe and Central Asia, but also in Western Europe and North America.

The malware, which the company is calling "Red October" after the 1990 Tom Clancy espionage thriller, targeted government institutions such as embassies, nuclear research centers and oil and gas institutes.

Kaspersky is publishing the entire research that led to the discovery of the cyber attack on its Web site.

"During the past five years, a high-level cyber-espionage campaign has successfully infiltrated computer networks at diplomatic, governmental and scientific research organizations, gathering data and intelligence from mobile devices, computer systems and network equipment," it reads.

"The campaign, identified as "Rocra", short for "Red October", is currently still active with data being sent to multiple command-and-control servers, through a configuration which rivals in complexity the infrastructure of the Flame malware. Registration data used for the purchase of C&C domain names and PE timestamps from collected executables suggest that these attacks date as far back as May 2007."

Kaspersky said it found several Russian words embedded in the malware's code, suggesting the attackers are of Russian-speaking origin. Words such as "Zakladka" appear in the malware, which, in Russian and Polish, can mean "bookmark" or "undeclared functionality" in slang.

Howeverr, Vitaly Kamluk, chief malware analyst at Kasperksy Lab, told TechWeekEurope there was no "strict evidence" a nation state was behind the attack. It was, nevertheless, one of the most targeted campaigns seen to date

"In Red October, the attackers seem to be hunting for specific organisations. They are interested in high-quality, high-profile information," Kamluk told TechWeekEurope. "That explains why the number of infected machines is so low - just over 300 machines... but every target was specifically selected. What makes this attack different from Flame and others is that every attack was planned very carefully.

"They shaped every attack attempt very carefully, and even created specific modules for targets. Not all the targets received the same binaries.

"Inside the malware, you can find a user ID, which actually shows it is a specific piece of malware compiled for a specific [target]."

Kaspersky said that it named the virus Red October because it was first brought to its attention in October 2012 after a tipoff from an anonymous source. The antivirus firm intends to publish the full report into the spy campaign later this week on its Web site.