Internet security firms in Japan have warned of a new computer virus that is increasingly affecting domestic companies.
The virus, which goes under the name "mstmp" among others, is designed to infiltrate websites to steal passwords and other information stored in personal computers.
Internet security company Trend Micro says the number of businesses hit by the malicious software has risen sharply since the end of September. It says more than 100 companies have been infected by the virus.
Another cyber security firm, LAC, says it is possible the virus is spreading through foreign IT services for gathering data on website visitors.
The exact nature of damage caused by the virus remains unclear.