One of the most complicated computer viruses that has apparently been used to spy on governments has been uncovered.

ONE of the most complicated and deadly computer viruses has been uncovered by internet security company Symantec.

The complex malware can disguise itself as legitimate Microsoft software and is designed to steal data from infected systems, which Symantec claims can take screenshots, control the cursor and even steal passwords.

Named Regin, the highly sophisticated software is believed to have been created by a government and most likely took months, if not years, to develop. It has been used to attack individuals and small businesses as well as private companies, government entities and research institutes.

Telecoms companies have also been infected, allowing hackers to gain access to phone calls.

Sian John, a security strategist at Symantec, said, “It looks like it comes from a Western organisation. It’s the level of skill and expertise, the length of time over which it was developed.”

Computers can be infected with the software through means including fake internet sites and instant messenger programs. It is unusually low-key, meaning that it can be used on a target for several years before being noticed.

Which country has been spying on these other countries using the long term deep seated spyware called #Regin? pic.twitter.com/03TxLijdaT — Vertebrate (@GreenGrounded) November 23, 2014

Symantec’s report claims Ireland has been the site of 9 per cent of confirmed infections and Russia, Saudi Arabia and Mexico have also been heavily affected. However, no country is immune from the virus.

The report describes the purpose of Regin as “intelligence gathering” and says: “It is used for the collection of data and continuous monitoring of targeted organisations or individuals.”

While they remain unconfirmed, initial reports have linked the malware to US and British intelligence services.

“Having analysed this malware and looked at the [previously published] Snowden documents, I’m convinced Regin is used by British and American intelligence services,” Ronald Prins, a security expert who was hired to conduct the investigation, told The Intercept.

As the malware was built for the purpose of surveillance and appears to be the work of a nation state, the internet is alive with speculation over who is behind the malicious software.

NEW: Secret Malware in European Union Attack Linked to U.S. and British Intelligence https://t.co/alKJ4BCYu4 #Regin — Glenn Greenwald (@ggreenwald) November 24, 2014

I wonder how many AV vendors, in addition to @FSecure, found Regin and were asked not to talk about it: https://t.co/gPkvDoDAIN — Runa A. Sandvik (@runasand) November 24, 2014

Symantec thinks #Regin, one of the most sophisticated malicious software seen, was created by a western government http://t.co/v2bsFndaH7 — Anonymous (@AnonPress) November 24, 2014

Monday's most intriguing story: “Regin” virus malware targeting #Russia "probably run by Western intelligence agency" http://t.co/qMK5LXRVlD — Jon Williams (@WilliamsJon) November 24, 2014

Cyber security has moved to the forefront of both modern warfare and intelligence gathering as governments seek to protect themselves and collect information on the activities of other nations.

There has been a number of high profile breaches that the US have speculated were committed by Chinese hackers with the FBI saying that all big US firms were likely to have been hacked.

Australia has also been the victim of cyber warfare with the ABC reporting last year that Chinese hackers stole the blueprints for Australia’s new ASIO building in Canberra.

At the moment, no government has released a statement on the Regin virus but speculation over its creator is sure to intensify.