The CIH virus struck hardest among countries where pirated software was most prolific, according to software company Data Fellows. The bug, which hit about 300 users – or 20 known companies - in the UK, caused most damage in Asia. Thousands of hard disks were overwritten overnight on 25 and 26 May in Taiwan alone, says the anti-virus and encryption company. Jason Holloway, Data Fellows UK country manager, described these traditional centres for counterfeit software as breeding grounds for CIH. "In countries like Taiwan, where users are not reluctant to use illegal software, the CIH virus has done the most damage. This is because viruses can be carried in the copied software," he said. CIH was also believed to have disabled 230 PCs at one police force in Africa. Holloway warned: "Users think that once they have bought anti-virus software, they are safe. But it must be updated to be effective - we discover six to seven new viruses per day." The author of CIH – or the Chernobyl virus as it is also known – has been identified as one Chen Ing-hau. The former student of the Tatung Institute of Technology named the virus using his initials. Just as well he didn't name it after the initials of his former college. ®