Iranian Oil Ministry\'s Spokesman Alireza Nikzad-Rahbar told Shana that the lion\'s share of the ministry\'s computer systems, including the Administrative Automation System have recommenced their activities since Tuesday evening. \"Thanks God, at the time being the computer systems are running with a high level of safety and users are working normally,\" he said. He further noted the efforts made by the ministry\'s IT experts to launch other computer systems, and said that the remaining sectors also resumed operation on Wednesday. Earlier, he had said the cyber attack had not caused damage to essential data of the ministry due to separation of main servers from public servers. \"Whether essential or non-essential, the oil ministry\'s data have a back up,\" he said, adding the ministry has the capability to repel cyber attacks which is the result of its strong engineering and technical potentials. He confirmed that some minor public data had been damaged which include mainly users\' data. According to the oil ministry, the cyber attack was carried out through a virus penetration that damaged users\' hard disks.