In articles published on September 12 and 13, UK newspapers claim that a group of Greek hackers had gained access to one of the computers on the CERN network on the day the first tests with the Large Hadron Collider (LHC) started.

According to The Telegraph daily, the hackers "were 'one step away' from the computer control system of one of the huge detectors of the machine."

The Times daily said "insiders scoffed at claims that the hackers were 'one step away' from the systems controlling the experiment itself."

The computer system that appears to have been the target of the attack was the webserver of CMSMON, a system which monitors the software system of the Compact Muon Solenoid (CMS). The CMS is one of the detectors used in the LHC and consists largely of a magnet that weighs 12500 tons, measures 21m in length and is 15m in diameter.

The hackers put up a rogue webpage on the server. The Telegraph published a screenshot of the page. In the text on the page the hackers called themselves Greek Security Team and referred to the IT security staff on the project as "a bunch of schoolkids."

The hackers said they had no intention of disrupting the tests.

"We're pulling your pants down because we don't want to see you running around naked looking to hide yourselves when the panic comes," both The Telegraph and The Times quoted the posting in Greek left by the hackers.

The CMS is one of the parts of the LHC project where Bulgarian scientists contributed.

Bulgarian team leader Leander Litov, head of the nuclear physics department at Sofia University, told The Sofia Echo that if the hackers would have had access to the computer system that monitors the CMS, all they would have been able to do was look at the monitoring data.

James Gillies, spokesperson for CERN was quoted in UK press as saying "there seems to be no harm done. From what they can tell, it was someone making the point that CMS was hackable. It was quickly detected."

The computer system at CERN uses what is known as a defence-in-depth strategy, in which information is protected by building a number of layers around the information that work together, separating layers control network and using and complex passwords.

Public webservers are in the outside layers, while the computers that control the experiment are at the very core.

The Telegraph quoted an unnamed scientist working on the machine that was hacked as saying "we think that someone from Fermilab's Tevatron (the competing atom smasher in America) had their access details compromised."

"What happened wasn't a big deal, just goes to show people are out there always on the prowl," the scientist was quoted as saying.