The Iranian National Computer Emergency Response Team announced it was ready to distribute software to protect against a type of malware dubbed Flame.
Iran in April unplugged computer servers from an oil terminal at Kharq Island following a virus outbreak believed to have been caused by the Flame malware.
Graham Cluley, a technology consultant at computer security company Sophos, told the BBC that the specificity of the virus made it difficult to detect. Authorities said the complexity of the program used in Flame suggests it was developed by a national government rather than cybercriminals.
The United Nation's International Telecommunications Union called on computer security experts to investigate the malware after a number of computers in the Middle East were wiped clean of data.
Tehran said the attack targeted the Web sites of the Iranian Oil Ministry, the National Iranian Oil Co. and "a number" of companies tied to the energy sector.
Iran was the largest country hit by the Flame infections.